Basic or Neet Biology

The living world is related to life and the life is all around us, from the towering trees in a forest to the tiniest microorganisms in a drop of water. The living world possess a remarkable set of characteristics that define their existence. These characteristics encompass everything from the way they are structured to how they interact with their environment and reproduce.

The Living World and What is Living?

In the living world the living refers to the state of being alive or having the qualities of life. Living organisms are those entities that exhibit certain characteristics which differentiate them from non-living matter. These characteristics include organization, metabolism, growth, adaptation, response to stimuli, reproduction, and evolution.

Biodiversity

The living world is related with biodiversity. Biodiversity is the incredible variety of life forms that exist on our planet, from the smallest microorganisms to the largest mammals. It encompasses the richness of ecosystems, species, and genetic diversity, forming the intricate web of life that sustains our world.

Definition of Biodiversity:

Biodiversity refers to the variety of life forms found in a particular habitat, ecosystem, or on Earth as a whole. It encompasses the diversity of species, genes, and ecosystems, including everything from the smallest bacteria to the largest mammals and from the genes within a single species to the complex interactions between different species in an ecosystem.

Types of Biodiversity:

Biodiversity can be categorized into several types, each representing a different aspect of the variety of life on Earth.

Types of Biodiversity	Description	Examples
Species Diversity	Refers to the variety and abundance of different species within an ecosystem or habitat. It includes both the number of species present and their relative distribution. High species diversity indicates a healthy and resilient ecosystem, while low species diversity may signify environmental stress or disturbance.	A rainforest with a wide array of plant and animal species, including trees, birds, insects, and mammals.
Genetic Diversity	Encompasses the variety of genetic information within and between populations of the same species. It includes differences in DNA sequences, gene frequencies, and allelic variation. Genetic diversity is essential for the adaptability and resilience of populations, allowing them to evolve and survive in changing environments.	Variability in the DNA sequences and gene frequencies of different breeds of domestic dogs.
Ecosystem Diversity	Represents the variety of different ecosystems or habitat types present within a region. It includes terrestrial ecosystems such as forests, grasslands, and wetlands, as well as aquatic ecosystems such as rivers, lakes, and coral reefs. Each ecosystem has its own unique characteristics and species composition, contributing to overall biodiversity.	Coastal ecosystems such as mangrove forests, salt marshes, and coral reefs, each with its own unique characteristics and species composition.

Need for classification

The living world needs classification is the process of organizing and categorizing objects, organisms, or concepts based on shared characteristics or attributes. From the natural world to human-made systems, classification plays a crucial role in helping us make sense of the complexity and diversity of the world around us.

1. Organization and Structure: Classification provides a framework for organizing information and creating structure. By grouping similar objects or organisms together, we can better understand their relationships and identify patterns and trends. For example, in biology, organisms are classified into hierarchical categories such as kingdoms, phyla, and species, allowing scientists to study and compare different groups of organisms systematically.
2. Communication and Language: Classification facilitates communication by providing a common language and terminology for describing and referencing objects or concepts. For instance, in libraries, books are classified according to the Dewey Decimal Classification system, making it easier for patrons to locate specific books on shelves based on subject matter. Similarly, scientific classification systems such as the periodic table of elements enable scientists to communicate complex ideas and findings effectively.
3. Problem-Solving and Decision-Making: Classification helps us analyze and solve problems by organizing data and information in a meaningful way. In fields such as medicine and engineering, classification systems are used to diagnose diseases, design solutions, and make informed decisions. For example, in healthcare, the International Classification of Diseases (ICD) provides a standardized system for classifying and coding medical diagnoses and procedures, facilitating accurate diagnosis and treatment.
4. Understanding Diversity and Relationships: Classification allows us to recognize and appreciate the diversity of the natural world and understand the relationships between different entities. By classifying organisms into taxonomic groups based on shared characteristics, biologists can study evolutionary relationships and trace the history of life on Earth. Additionally, classification helps us identify species at risk of extinction and prioritize conservation efforts to protect biodiversity.
5. Education and Learning: Classification is a fundamental concept taught in schools and educational institutions, providing students with valuable skills in critical thinking, observation, and categorization. Learning how to classify objects, organisms, or concepts helps students develop logical reasoning and problem-solving abilities that are essential for success in various academic disciplines and real-world scenarios.

Three domains of life

In the living world, life on Earth is remarkably diverse, with millions of species ranging from microscopic bacteria to large trees and majestic mammals. To understand this vast array of organisms, scientists have classified them into three primary domains based on their cellular structure and genetic makeup.

Bacteria (Domain Bacteria):

Bacteria are single-celled microorganisms that are found in almost every environment on Earth. They come in a wide variety of shapes, sizes, and lifestyles, from rod-shaped bacteria living in soil to spiral-shaped bacteria thriving in extreme environments like hot springs. Despite their small size, bacteria play crucial roles in ecosystems, such as decomposing organic matter, fixing nitrogen, and even causing diseases. In the living world, bacteria lack a nucleus and other membrane-bound organelles, and their genetic material is typically found in a single circular chromosome.

Archaea (Domain Archaea):

Archaea are another group of single-celled microorganisms, similar to bacteria in size but distinct in their genetic makeup and biochemical processes. Archaea are known for their ability to survive in extreme environments such as hot springs, deep-sea hydrothermal vents, and salt flats. In the living world, they have unique cell membranes and cell walls and often utilize unusual metabolic pathways not found in bacteria or eukaryotes. Archaea are crucial for nutrient cycling and energy production in extreme environments and contribute to the overall functioning of ecosystems.

Eukarya (Domain Eukarya):

Eukaryotes are organisms with complex cells containing a nucleus and other membrane-bound organelles. In the living world, this domain includes a vast diversity of organisms, ranging from microscopic protists to multicellular plants, animals, and fungi. Eukaryotes exhibit a wide range of forms and lifestyles, from photosynthetic algae harnessing sunlight for energy to animals hunting for food in diverse habitats. Eukaryotes are found in almost every ecosystem on Earth and play essential roles in nutrient cycling, energy flow, and ecosystem stability.

In the living world, these 3 domains of life share a common factor called biomolecules. If you want to know more about biomolecules then read the article: 5 Major Biomolecules in Life | Chemical Constituents of Life.

 Taxonomy and Systematics

In the living world, Taxonomy and systematics are two branches of biology that focus on organizing and classifying living organisms based on their evolutionary relationships, characteristics, and shared traits. These fields play a crucial role in helping scientists understand the diversity of life on Earth and how different species are related to each other.

Taxonomy:

Taxonomy is the science of naming, describing, and classifying organisms into hierarchical groups based on shared characteristics. The primary goal of taxonomy is to provide a systematic framework for organizing and categorizing the vast diversity of life. In the living world, at the heart of taxonomy is the taxonomic hierarchy, which starts with broad categories and becomes increasingly specific at lower levels. The highest level of classification is the domain, followed by kingdom, phylum, class, order, family, genus, and species.

Systematics:

Systematics, on the other hand, is the study of the evolutionary relationships between organisms and how they are classified into different groups. In the living world, systematics utilizes various methods and techniques, including molecular biology, comparative anatomy, and fossil records, to reconstruct the evolutionary history of organisms and develop phylogenetic trees. These trees represent the branching patterns of evolutionary relationships, with closely related species sharing a more recent common ancestor than distantly related ones.

Similarities Between Taxonomy and Systematics:

Aspect	Similarities
Classification	Both taxonomy and systematics involve the classification of organisms into hierarchical groups based on shared characteristics and evolutionary relationships.
Hierarchical Classification	Both fields use a hierarchical system of classification, starting with broad categories and becoming increasingly specific at lower levels.
Organism Classification	Both taxonomy and systematics focus on studying the diversity of life and understanding the relationships between different organisms.
Scientific Importance	Both fields are integral to the study of biology and are used by scientists to organize biological knowledge and facilitate communication among researchers.
Interdisciplinary Approach	Both fields draw on principles from various branches of biology, including genetics, anatomy, ecology, and molecular biology.

Let’s Visualize The Chapter

Differences Between Taxonomy and Systematics:

Aspect	Taxonomy	Systematics
Definition	The science of naming, describing, and classifying organisms into hierarchical groups based on shared characteristics.	The study of the evolutionary relationships between organisms and how they are classified into different groups.
Focus	Focuses on the classification and categorization of organisms.	Focuses on understanding the evolutionary history and relationships among organisms.
Goals	Provides a systematic framework for organizing and categorizing the diversity of life.	Aims to reconstruct phylogenetic relationships and develop phylogenetic trees.
Methods	Utilizes morphological, anatomical, genetic, and other characteristics to classify organisms.	Utilizes molecular biology, comparative anatomy, fossil records, and other techniques to reconstruct evolutionary history.
Application	Used for naming and organizing organisms into hierarchical groups (e.g., kingdom, phylum, class,	Used to understand the evolutionary relationships
	hierarchical groups (e.g., kingdom, phylum, class, order, family, genus, species).	between organisms, predict responses to environmental changes, and inform conservation efforts.
Interdisciplinary	Draws on principles from various branches of biology, including genetics, morphology, and ecology.	Integrates multiple disciplines, including genetics, ecology, paleontology, and molecular biology.

Concept of Species and Taxonomical Hierarchy

In the living world, the concept of species and taxonomical hierarchy serves as a guiding framework, allowing scientists to organize and understand the incredible diversity of living organisms.

Species:

A species is a group of organisms that share similar characteristics and can interbreed to produce fertile offspring. This definition may seem straightforward, but in reality, the concept of a species in the living world, can be complex and nuanced. For sexually reproducing organisms, such as animals and plants, the ability to interbreed is a key criterion for defining a species. However, for asexual organisms or those with limited mobility, such as bacteria or plants, other factors such as genetic similarity and ecological niche may be used to delineate species boundaries.

Taxonomical Hierarchy:

The taxonomical hierarchy is a system of classification that organizes living organisms into hierarchical groups based on their evolutionary relationships and shared characteristics. This hierarchical structure in the living world, starts with broad categories and becomes increasingly specific at lower levels. The highest level of classification is the domain, followed by kingdoms, phyla, classes, orders, families, genera, and species.

Level	Description	Example
Domain	The highest level of classification, representing broad categories of organisms based on fundamental differences.	Eukarya (includes plants, animals, fungi, etc.)
Kingdom	Subdivisions within domains, grouping organisms with similar characteristics and evolutionary histories.	Animalia (animals), Plantae (plants), Fungi
Phylum	Major evolutionary branches within kingdoms, representing distinct body plans and structural characteristics.	Chordata (vertebrates), Arthropoda (arthropods)
Class	Further subdivisions within phyla, grouping organisms with similar anatomical features and developmental patterns.	Mammalia (mammals), Insecta (insects)
Order	Groups of related families within classes, representing shared characteristics and evolutionary relationships.	Carnivora (carnivores), Rodentia (rodents)
Family	Collections of related genera within orders, sharing common ancestry and genetic similarities.	Felidae (cats), Canidae (dogs)
Genus	Groups of closely related species within families, sharing a common evolutionary origin and anatomical features.	Panthera (lions, tigers), Canis (wolves, dogs)
Species	The most specific level of classification, identifying individual groups of organisms that can interbreed.	Panthera leo (lion), Canis lupus (wolf)

Binomial Nomenclature

In the living world, the binomial nomenclature is a brilliant system devised by the Swedish scientist Carl Linnaeus in the 18th century, which has become the cornerstone of modern biological classification.

Binomial nomenclature is essentially a fancy term for a simple concept: the naming of species using two words. It’s like giving each species its own unique first and last name. Let’s break it down.

The first word in a species’ name is its genus, which is a group of closely related species that share common characteristics. Think of it like a family surname, indicating broader relationships. The genus name is always capitalized.

The second word is the species epithet, which is like an individual’s given name. It distinguishes one species from another within the same genus. The species epithet is always written in lowercase.

For example, consider the scientific name for humans: Homo sapiens. “Homo” is our genus, indicating that we belong to the same group as other great apes like chimpanzees and gorillas. “Sapiens” is our species epithet, unique to modern humans.

Binomial nomenclature provides several benefits. First and foremost, it offers a standardized and universally recognized way of referring to species. This means that scientists from different countries and backgrounds can communicate effectively without getting lost in translation.

Secondly, binomial nomenclature helps avoid confusion caused by different common names for the same species. For instance, the common name “jaguar” might refer to the same species in English, Spanish, or Portuguese, but its scientific name, Panthera onca, remains consistent across languages.

Furthermore, binomial nomenclature reflects the evolutionary relationships between species. Species within the same genus are closely related, sharing a common ancestor. This hierarchical system of classification allows scientists to trace the evolutionary history of organisms and understand their place in the tree of life.

Common Name	Scientific Name	Type
Dog	Canis lupus familiaris	Animal
Cat	Felis catus	Animal
Tiger	Panthera tigris	Animal
Lion	Panthera leo	Animal
Elephant	Elephas maximus	Animal
Giraffe	Giraffa camelopardalis	Animal
Gorilla	Gorilla gorilla	Animal
Chimpanzee	Pan troglodytes	Animal
House Mouse	Mus musculus	Animal
Brown Bear	Ursus arctos	Animal
Rose	Rosa spp.	Plant
Oak	Quercus spp.	Plant
Wheat	Triticum aestivum	Plant
Sunflower	Helianthus annuus	Plant
E. coli	Escherichia coli	Bacteria
Bacillus anthracis	Bacillus anthracis	Bacteria
Saccharomyces cerevisiae	Saccharomyces cerevisiae	Bacteria
Human Immunodeficiency Virus	Human Immunodeficiency Virus	Virus
Influenza A virus	Influenza A virus	Virus

Tools for Study of Taxonomy

In the living world, taxonomy is the science of classifying and naming living organisms, and relies on various tools and resources to help researchers understand the vast diversity of life on Earth. Museums, zoological parks, herbaria, and botanical gardens are essential institutions that provide valuable resources and support for the study of taxonomy.

Museums:

Natural history museums house vast collections of specimens, including fossils, skeletons, preserved organisms, and other artifacts. These collections serve as invaluable resources for taxonomists, providing a wealth of physical specimens for study and comparison. Museums also often employ taxonomists and researchers who study and curate these collections, contributing to our understanding of evolutionary relationships and biodiversity.

Zoological Parks:

Such as zoos and aquariums, play a crucial role in taxonomy by providing opportunities for the study and observation of live animals. Zoos house diverse animal species from around the world, allowing researchers to study their behavior, morphology, and genetics. By studying live animals, taxonomists can observe unique behaviors, reproductive patterns, and ecological interactions, providing insights into their evolutionary history and conservation needs.

Herbaria:

Herbaria are collections of preserved plant specimens, including dried plant specimens, seeds, and other plant parts. These collections are essential for the study of plant taxonomy, providing physical specimens for identification, classification, and research. Herbaria also serve as repositories of plant diversity, housing specimens from diverse geographic regions and time periods. Researchers can study these specimens to understand plant distributions, evolutionary relationships, and ecological adaptations.

Botanical Gardens:

Botanical gardens are living museums that showcase diverse plant species in curated gardens and landscapes. These gardens often specialize in specific plant groups or ecosystems, providing opportunities for researchers to study plant diversity, ecology, and conservation. Botanical gardens also conduct research, conservation, and educational programs, contributing to our understanding of plant taxonomy and biodiversity conservation.

Institution	Description	Examples	Indian Examples
Museum	Institutions that preserve and display collections of artifacts, specimens, and objects of cultural, historical, or scientific significance.	– American Museum of Natural History (AMNH) – British Museum – Smithsonian National Museum of Natural History	– Indian Museum, Kolkata – National Museum, New Delhi – Salar Jung Museum, Hyderabad
Zoological Park	Facilities that house and exhibit live animals for public display, education, research, and conservation purposes.	– San Diego Zoo – London Zoo – Singapore Zoo	– Arignar Anna Zoological Park, Chennai – Delhi Zoo (National Zoological Park) – Bannerghatta Biological Park, Bangalore
Herbarium	Collections of preserved plant specimens, including dried plants, seeds, and other plant parts, used for scientific study and research in botany and plant taxonomy.	– Harvard University Herbaria – Royal Botanic Gardens, Kew – New York Botanical Garden Herbarium	– Botanical Survey of India, Kolkata – Bombay Natural History Society, Mumbai – French Institute of Pondicherry
Botanical Garden	Living museums that showcase diverse plant species in curated gardens and landscapes, used for research, education, and conservation of plant biodiversity.	– Royal Botanic Gardens, Kew – New York Botanical Garden – Singapore Botanic Gardens	– Lal Bagh Botanical Garden, Bangalore – Indian Botanical Garden, Howrah – Nehru Zoological Park, Hyderabad

The concept of the living world encompasses a remarkable array of characteristics and behaviors unique to organisms. While defining life in the living world, precisely may pose challenges, in the dynamic processes that distinguish living organisms from non-living matter, understand the intricate web of life.

FAQs on The Living World

Step into the vibrant world of the plant kingdom classification chart! Plants, the green architects of our planet, are grouped into various categories based on shared characteristics. The primary division lies between vascular and non-vascular plants. Vascular plants, like trees and ferns, have specialized tissues for water and nutrient transport, while non-vascular plants, such as mosses, lack these structures. Within these groups, plants are further classified into families based on distinct features and adaptations.

Plant Kingdom Classification Chart

The below outlines the plant kingdom classification chart of plants into major groups, highlighting their characteristics and evolutionary relationships.

1. Algae (Division: Chlorophyta, Phaeophyta, Rhodophyta)
   • Multicellular or unicellular photosynthetic organisms
   • Found in aquatic environments
   • Examples: Green algae, Brown algae, Red algae
2. Bryophyta (Division: Bryophytes)
   • Non-vascular plants
   • Lack specialized tissues for water and nutrient transport
   • Examples: Mosses, Liverworts, Hornworts
3. Pteridophyta (Division: Pteridophytes)
   • Vascular plants
   • Reproduce via spores
   • Examples: Ferns, Clubmosses, Horsetails
4. Gymnospermae (Division: Gymnosperms)
   • Vascular plants
   • Seeds not enclosed in a fruit
   • Examples: Conifers (Pines, Spruces, Firs), Cycads, Ginkgo
5. Angiospermae (Division: Angiosperms)
   • Vascular plants
   • Seeds enclosed in a fruit
   • Further divided into two classes:
   a. Monocotyledons (Class: Monocots)
   • Have one cotyledon (seed leaf) in the embryo
   • Parallel leaf venation
   • Examples: Grasses, Lilies, Orchids
   b. Dicotyledons (Class: Dicots)
   • Have two cotyledons in the embryo
   • Netted leaf venation
   • Examples: Roses, Sunflowers, Oak Trees

If you want to know about the first chapter, then read the article: The Living World – Full Chapter Here.

Salient and Distinguishing Features of Algae:

In the plant kingdom classification chart, Algae, often overlooked in favor of their larger, leafy counterparts, are fascinating and diverse organisms that play crucial roles in ecosystems around the globe. From the vibrant green of freshwater ponds to the majestic kelp forests of the ocean depths, algae come in a dazzling array of forms and colors.

Criteria	Features
Habitat	Algae are simple, chlorophyll-bearing organisms that are primarily found in aquatic environments, including both freshwater and marine habitats. However, they can also be found in a variety of other settings, such as moist stones, soils, and wood. Some algae even form symbiotic relationships with fungi, as seen in lichens, or with animals, like those found on sloth bears.
Size	The size and form of algae vary widely, ranging from colonial forms like Volvox to filamentous forms like Ulothrix and Spirogyra. In marine environments, certain algae, such as kelps, can form massive plant bodies.
Reproduction	Algae reproduce through vegetative, asexual, and sexual methods. Vegetative reproduction occurs through fragmentation, where each fragment develops into a new thallus. Asexual reproduction involves the production of spores, with zoospores being the most common type. These spores are flagellated and give rise to new plants upon germination. Sexual reproduction occurs through the fusion of two gametes, which can be flagellated and similar in size (isogamous) or non-flagellated but similar in size (anisogamous). In some species, such as Volvox and Fucus, sexual reproduction involves the fusion of a large, non-motile female gamete with a smaller, motile male gamete (oogamous).
Roles in Ecosystem	Algae play significant roles in ecosystems and are beneficial to humans in various ways. They are responsible for a considerable portion of carbon dioxide fixation through photosynthesis, thereby increasing oxygen levels in their surroundings. As primary producers, they form the basis of the food chains for aquatic animals.
Commercial Importance	Many species of marine algae, including Porphyra, Laminaria, and Sargassum, are consumed as food. Additionally, certain types of marine brown and red algae produce hydrocolloids, such as algin and carrageen, which are used commercially. Agar, derived from algae like Gelidium and Gracilaria, is utilized in microbiology and food products like ice creams and jellies. Chlorella, a unicellular alga rich in proteins, is used as a dietary supplement, even by astronauts.
Classification	In the plant kingdom classification, Algae are classified into three main classes: Chlorophyceae (green algae), Phaeophyceae (brown algae), and Rhodophyceae (red algae)

Examples and Differences of Algae:

Feature	Chlorophyceae (Green Algae)	Phaeophyceae (Brown Algae)	Rhodophyceae (Red Algae)
Pigment Composition	Chlorophylls a and b, carotenoids	Chlorophylls a and c, fucoxanthin, xanthophylls	Chlorophylls a and d, phycoerythrin, phycocyanin
Habitat	Freshwater, marine, terrestrial	Predominantly marine, some freshwater species	Predominantly marine, some freshwater and terrestrial
Coloration	Typically green, although some may appear yellow or red	Typically brown, ranging from olive to dark brown	Typically red or purple, although some may appear green
Cell Wall Composition	Cellulose	Cellulose, algin	Cellulose, agar, carrageenan
Structure and Form	Variable, may be unicellular, colonial, or filamentous	Variable, ranging from simple filaments to complex	Variable, ranging from filamentous to multicellular
Photosynthetic Structures	Chloroplasts with stacked thylakoids	Chloroplasts with unstacked thylakoids	Chloroplasts with unstacked thylakoids
Ecological Importance	Primary producers, important in freshwater ecosystems	Found in rocky intertidal zones, provide habitat	Important contributors to coral reef ecosystems
Economic Significance	Used in research, food sources, and wastewater treatment	Commercially harvested for algin and hydrocolloids	Commercially harvested for agar, carrageenan, and food
Examples	Chlamydomonas, Volvox	Fucus, Laminaria	Porphyra, Corallina

Salient and Distinguishing Features of Bryophyta:

Bryophytes, often referred to as mosses and liverworts, are a group of small, non-vascular plants that play essential roles in ecosystems worldwide. Despite their diminutive size, these plants boast a range of unique features and adaptations that set them apart from other plant groups.

Watch The Video of Moss Here

Criteria	Features
Habitat	Bryophytes encompass various mosses and liverworts, commonly found thriving in shaded, moist areas, particularly in hilly regions. Often referred to as the “amphibians of the plant kingdom,” bryophytes can survive in soil but rely on water for sexual reproduction. They typically inhabit damp, humid, and shaded environments, playing a crucial role in plant succession on bare rocks or soil.
Structure	The plant body of bryophytes is more complex compared to algae, exhibiting a thallus-like structure that can be prostrate or erect, with attachment to the substrate facilitated by unicellular or multicellular rhizoids. True roots, stems, or leaves are absent, though they may possess structures resembling roots, leaves, or stems.
Reproduction	The primary plant body of bryophytes is haploid and known as a gametophyte, producing multicellular sex organs. The male sex organ, called an antheridium, produces biflagellate antherozoids, while the female sex organ, called an archegonium, produces a single egg. Upon fertilization, the zygote develops into a sporophyte, which remains attached to the photosynthetic gametophyte and obtains nourishment from it. Some sporophyte cells undergo reduction division (meiosis) to produce haploid spores, which germinate to form new gametophytes.
Economic Importance	While bryophytes generally hold little economic significance, certain moss species serve as food for herbivorous mammals, birds, and other animals. Sphagnum moss, for instance, provides peat, historically used as fuel and packing material due to its water-retaining properties. Mosses, along with lichens, are pioneers in colonizing rocks, playing a vital ecological role in rock decomposition and soil formation. Dense moss mats on soil mitigate the impact of rainfall and prevent soil erosion.
Classification	In the plant kingdom classification, Bryophytes are classified into liverworts and mosses, each contributing to ecological processes and ecosystem stability in their unique ways.

Examples and Differences of Bryophyta:

Criteria	Liverworts	Mosses
Habitat	Liverworts typically thrive in moist and shaded environments, such as stream banks, marshy areas, damp soil, tree bark, and deep within forests.	Mosses are commonly found in moist and shaded areas, such as forests, wetlands, and along stream banks. They can also inhabit more extreme environments, including arctic tundras and deserts
Structure	The plant body of a liverwort is thalloid in structure, exemplified by species like Marchantia. The thallus is dorsiventral, meaning it has distinct upper and lower surfaces, and closely adheres to the substrate. Leafy liverworts feature tiny leaf-like structures arranged in two rows along stem-like structures.	The primary phase of the moss life cycle is the gametophyte stage, which comprises two distinct phases. The initial phase is known as the protonema stage, originating directly from a spore. It manifests as a creeping, green, and often filamentous structure, branching out extensively. The subsequent phase is the leafy stage, emerging from the secondary protonema as a lateral bud. This stage features upright, slender axes adorned with spirally arranged leaves and anchored to the soil by multicellular and branched rhizoids. It is within this stage that the reproductive organs are located.
Asexual Reproduction	Asexual reproduction in liverworts occurs through thallus fragmentation or the formation of specialized structures known as gemmae (singular: gemma). Gemmae are multicellular, green, asexual buds that develop within small receptacles called gemma cups on the thallus. These gemmae detach from the parent body and germinate to give rise to new individuals.	Mosses reproduce vegetatively through fragmentation and budding within the secondary protonema.
Sexual Reproduction	During sexual reproduction, liverworts produce male and female sex organs, which may occur on the same thallus or on separate ones. The sporophyte, differentiated into a foot, seta, and capsule, develops after fertilization. Meiosis within the capsule produces spores, which germinate to form independent gametophytes, completing the life cycle of liverworts.	In sexual reproduction, specialized structures called antheridia and archegonia develop at the tips of the leafy shoots. Upon fertilization, the zygote matures into a sporophyte, comprising a foot, seta, and capsule. Unlike liverworts, moss sporophytes are comparatively more intricate. The capsule houses spores, which are produced through meiosis. Mosses exhibit a sophisticated mechanism for spore dispersal.
Examples	Marchantia polymorpha, Marchantia berteroana, Conocephalum conicum, Pellia epiphylla, Riccia fluitans	Funaria hygrometrica, Polytrichum commune, Sphagnum palustre

Salient and Distinguishing Features and Examples of Pteridophyta:

In the plant kingdom classification chart, Pteridophytes encompass horsetails and ferns and are utilized for medicinal purposes and as agents for binding soil. They are commonly cultivated for their ornamental value as well. Evolutionarily, they represent the earliest terrestrial plants to possess vascular tissues—xylem and phloem.

Criteria	Features
Habitat	Pteridophytes are typically found in cool, damp, shaded environments, although some species thrive in sandy soil conditions.
Structure	The dominant phase is the gametophytic plant body, pteridophytes primarily feature a sporophyte as the main plant body. This sporophyte is differentiated into true roots, stems, and leaves, each equipped with well-defined vascular tissues. The leaves in pteridophytes can vary in size, with some species exhibiting small leaves (microphylls), such as Selaginella, while others showcase large leaves (macrophylls), as seen in ferns. Sporophytes bear sporangia, which are accompanied by leaf-like structures known as sporophylls. In certain instances, sporophylls may form distinct compact structures called strobili or cones, as observed in Selaginella and Equisetum.
Asexual Reproduction	Sporangia produce spores through meiosis in spore mother cells. These spores germinate to generate inconspicuous, small yet multicellular, free-living thalloid gametophytes termed prothalli. These gametophytes typically necessitate cool, damp, and shaded environments for growth. Due to their specific requirements and reliance on water for fertilization, the distribution of living pteridophytes is limited and confined to narrow geographic regions.
Sexual Reproduction	Gametophytes bear male and female sex organs referred to as antheridia and archegonia, respectively. Water is essential for the transfer of antherozoids, the male gametes released from the antheridia, to the archegonium. Fusion between the male gamete and the egg within the archegonium results in the formation of a zygote. Subsequently, the zygote develops into a multicellular, well-differentiated sporophyte, representing the dominant phase of pteridophytes.
Development	In the majority of pteridophytes, all spores are of similar kinds, classifying them as homosporous. However, genera like Selaginella and Salvinia produce two kinds of spores—macro (large) and micro (small) spores—making them heterosporous. Megaspores and microspores germinate to produce female and male gametophytes, respectively. Female gametophytes in these plants are retained on the parent sporophytes for varying durations. The development of zygotes into young embryos within female gametophytes serves as a precursor to the seed habit, marking an important evolutionary milestone.
Examples	In the plant kingdom classification, Pteridophytes are further categorized into four classes: Psilopsida (Psilotum), Lycopsida (Selaginella, Lycopodium), Sphenopsida (Equisetum), and Pteropsida (Dryopteris, Pteris, Adiantum).

Salient and Distinguishing Features and Examples of Gymnosperm:

In the plant kingdom classification chart, Gymnosperms, derived from the Greek words “gymnos” meaning naked and “sperma” meaning seeds, refer to plants where the ovules lack an enclosing ovary wall, remaining exposed both before and after fertilization. Consequently, the seeds formed post-fertilization are uncovered, hence termed as naked seeds.

Criteria	Salient and Distinguishing Features
Habitat	Gymnosperms, including iconic species like pine, spruce, and cedar, inhabit a diverse array of environments worldwide. These resilient plants thrive in various habitats, from temperate forests and boreal regions to mountainous landscapes and coastal areas. Their adaptability allows them to flourish in environments with different climates, soil types, and elevations.
Structure	Gymnosperms encompass a range of medium to tall trees and shrubs, with notable examples including the towering giant redwood tree Sequoia.
Root System	Root systems in gymnosperms typically consist of tap roots, with some genera forming symbiotic associations with fungi in the form of mycorrhiza, as seen in Pinus, while others like Cycas exhibit coralloid roots associated with nitrogen-fixing cyanobacteria.
Stem System	Stems in gymnosperms may be either unbranched, as in Cycas, or branched, as in Pinus and Cedrus. The leaves may vary in complexity, being either simple or compound. For instance, in Cycas, the pinnate leaves persist for a few years.
Spores	Gymnosperms are heterosporous, producing haploid microspores and megaspores. These spores develop within sporangia borne on sporophylls, arranged spirally along an axis to form lax or compact strobili or cones.
Strobili or Cones	Strobili bearing microsporophylls and microsporangia are termed microsporangiate or male strobili, where microspores develop into a highly reduced male gametophyte called a pollen grain within the microsporangia. Cones bearing megasporophylls with ovules or megasporangia are termed macrosporangiate or female strobili. While male and female cones or strobili may be borne on the same tree in Pinus, in Cycas, male cones and megasporophylls are borne on different trees.
Reproduction	During fertilization, the pollen grain is released from the microsporangium, carried by air currents, and comes in contact with the opening of the ovules borne on megasporophylls. The pollen tube carrying the male gametes grows towards archegonia in the ovules and discharges its contents near the mouth of the archegonia. Following fertilization, the zygote develops into an embryo and the ovules into seeds, which remain uncovered.
Adaptability	Gymnosperm leaves are well-adapted to withstand extreme environmental conditions such as temperature, humidity, and wind. In conifers, needle-like leaves reduce surface area, while a thick cuticle and sunken stomata help reduce water loss. In pteridophytes, the male and female gametophytes in gymnosperms do not have an independent free-living existence, remaining within the sporangia retained on the sporophytes.
Examples	1. Pine: Pinus spp. (with various species such as Pinus sylvestris, Pinus ponderosa, etc.) 2. Spruce: Picea spp. (with various species such as Picea abies, Picea glauca, etc.) 3. Cedar: Cedrus spp. (with various species such as Cedrus atlantica, Cedrus deodara, etc.)

Salient and Distinguishing Features and Examples of Angiosperm:

Angiosperms, also known as flowering plants in the plant kingdom classification chart, represent a diverse group of plants characterized by the presence of flowers and enclosed seeds within fruits. This group includes a vast array of plant species, ranging from tiny herbs to towering trees like oak and maple.

How do plants grow watch here

Criteria	Features
Habitat	This diverse group of plants thrives in a wide array of habitats, ranging from the diminutive Wolffia to towering Eucalyptus trees exceeding 100 meters in height.
Structure	Angiosperms or flowering plants exhibit a distinctive reproductive structure known as flowers, within which both pollen grains and ovules develop. Furthermore, angiosperms encase their seeds within specialized structures called fruits.
Economic Importance	Angiosperms play pivotal roles in human society by providing essential resources such as food, fodder, fuel, medicines, and various other commercially significant products.
Classification	In the plant kingdom classification, they are classified into two main classes: dicotyledons and monocotyledons.

Differences Between Dicotyledons and Monocotyledons:

Feature	Dicotyledons (Dicots)	Monocotyledons (Monocots)
Seed Structure	Two cotyledons (seed leaves) present	Single cotyledon (seed leaf) present
Leaf Veins	Branched (net-veined)	Parallel veins
Stem Anatomy	Vascular bundles arranged in a ring	Vascular bundles scattered throughout the stem
Flower Parts	Typically in multiples of four or five	Typically in multiples of three
Root System	Taproot system	Fibrous root system
Growth Pattern	Secondary growth often present, resulting in woody stems	Secondary growth usually absent, stems herbaceous
Pollen Grains	Three furrows or pores (tricolpate)	One furrow or pore (monosulcate)
Germination	Hypocotyl elongates and forms a hook during germination	Hypocotyl remains short and straight during germination
Examples	Roses, oak trees, tomatoes, sunflowers	Grasses (e.g., wheat, rice), lilies, orchids

The plant kingdom classification chart provides a structured framework for understanding the vast diversity of plant life on Earth. This plant kingdom classification chart system not only aids in scientific research but also helps us appreciate the vital roles that plants play in sustaining life on our planet, from producing oxygen to providing food, shelter, and medicine.

FAQ on Plant Kingdom Classification Chart:

The animal kingdom classification chart, or kingdom Animalia, encompasses a vast array of living organisms that share certain fundamental characteristics. All animals are multicellular, eukaryotic organisms that primarily rely on consuming organic material for sustenance. They exhibit diverse forms and structures, ranging from simple sponges to complex mammals.

Keys to the Animal Kingdom Classification Chart:

Despite the structural and form differences among various animals, they share fundamental characteristics such as cell arrangement, body symmetry, coelom nature, and the patterns of their digestive, circulatory, and reproductive systems. These shared features serve as the foundation for the animal kingdom classification chart.

Criteria	Description	Examples
Level of Organization	The animal kingdom classification chart is based on their cellular organization: cellular, tissue, organ, and organ system levels.	Porifera (sponges) – cellular level; Cnidaria (jellyfish) – tissue level; Platyhelminthes (flatworms) – organ level; Chordata (vertebrates) – organ system level.
Body Symmetry	Symmetry refers to the arrangement of body parts around a central axis. Types include: Asymmetrical(No symmetry), Radial(Body parts arranged around a central axis), and Bilateral symmetry(Divisible into mirror-image halves).	Porifera (asymmetrical); Cnidaria (radial symmetry); Arthropoda (insects) and Chordata (mammals) – bilateral symmetry.
Germ Layers	The number of primary tissue layers during embryonic development: diploblastic (two layers) or triploblastic (three layers).	Cnidaria (diploblastic); Most other animal phyla including Chordata (triploblastic).
Body Cavity (Coelom)	The presence or absence of a body cavity between the digestive tract and body wall: Acoelomate(No body cavity), Pseudocoelomate(Partially lined cavity), and Coelomate(Fully lined body cavity).	Platyhelminthes (acoelomate); Nematoda (pseudocoelomate); Annelida, Mollusca, Arthropoda, Echinodermata, Chordata (coelomate).
Segmentation	The division of the body into repetitive segments. In certain animals, the body is divided both externally and internally into segments, with some organs repeating in each segment. For instance, in earthworms, this pattern is known as metameric segmentation, and the phenomenon is referred to as metamerism.	Annelida (earthworms), Arthropoda (insects), Chordata (vertebrates).
Notochord	Presence of a notochord, a flexible rod that supports the body in all embryonic and some adult stages.	Chordata (vertebrates and some invertebrates like tunicates and lancelets).
Presence of a Backbone	Vertebrates possess a vertebral column, while invertebrates do not.	Vertebrates: Chordata (fish, amphibians, reptiles, birds, mammals); Invertebrates: all other phyla (Arthropoda, Mollusca, etc.).
Reproductive Strategy	Mode of reproduction, including asexual (budding, fragmentation) and sexual reproduction (internal or external fertilization).	Cnidaria (both asexual and sexual); Arthropoda (mostly sexual with internal fertilization); Fish (external fertilization in many species).
Mode of Development	Developmental patterns such as direct development or indirect development (with larval stages).	Arthropoda (insects – indirect with metamorphosis); Mammals (direct development).
Thermoregulation	Mechanism to maintain body temperature: ectothermic (external sources) or endothermic (internal regulation).	Reptiles (ectothermic); Birds and Mammals (endothermic).
Habitat	The environment where animals live: terrestrial, aquatic (marine or freshwater), aerial, or amphibious.	Marine: Porifera, Cnidaria; Freshwater: Annelida; Terrestrial: Arthropoda, Mammals; Amphibious: Amphibians.

Chapter-1: The Living World

Animal Kingdom Classification Chart:

Porifera	Cellular level	Asymmetrical or radial	Acoelomate (No true body cavity)
Cnidaria	Tissue level	Radial symmetry	Acoelomate (No true body cavity)
Ctenophora	Tissue level	Radial symmetry	Acoelomate (No true body cavity)
Platyhelminthes	Organ level	Bilateral symmetry	Acoelomate (No body cavity)
Aschelminthes	Organ level	Bilateral symmetry	Pseudocoelomate (body cavity partially lined with mesoderm)
Annelida	Organ system level	Bilateral symmetry	Coelomate (true coelom fully lined with mesoderm)
Arthropoda	Organ system level	Bilateral symmetry	Coelomate (reduced in some to hemocoel)
Mollusca	Organ system level	Bilateral symmetry	Coelomate (coelom reduced around heart, nephridia, gonads)
Echinodermata	Organ system level	Radial symmetry (adults). Echinodermata exhibits radial or bilateral symmetry depending on the stage.	Coelomate (extensive coelom forming water vascular system).
Hemichordata	Organ system level	Bilateral symmetry	Coelomate (developed coelom)
Chordata	Organ system level	Bilateral symmetry	Coelomate (well-developed coelom)

Chapter-2: Biological Classification

Animal Kingdom Classification Chart: Phylum Porifera

Salient Features

Feature	Salient Features
Level of Organization	Cellular level; lacks true tissues and organs.
Body Symmetry	Asymmetrical or radial symmetry.
Body Structure	Possesses a porous body with numerous pores (ostia) allowing water to circulate through canals. Sponges possess a water transport or canal system. Water flows into the sponge through tiny pores called ostia in the body wall, enters a central cavity known as the spongocoel, and exits through a larger opening called the osculum.
Skeleton	Internal skeleton made of spicules (calcium carbonate or silica) or spongin fibers.
Feeding Method	Filter feeders; water flows through pores, trapping food particles which are then ingested by specialized cells.
Reproduction	Sexes are not separate (hermaphrodite), i.e., eggs and sperms are produced by the same individual. Can reproduce both sexually (via gametes) and asexually (budding, fragmentation).
Habitat	Mostly marine, with a few freshwater species.
Unique Cells	Choanocytes (collar cells) that create water currents and capture food particles.
Regeneration	High capacity for regeneration; can regrow from small fragments.
Ecological Role	Important in aquatic ecosystems for water filtration and providing habitat for other organisms.

Examples:

• Spongilla (freshwater sponge)
• Euplectella (Venus’ flower basket)
• Spongia (bath sponge)

Chapter-3: Plant Kingdom

Animal Kingdom Classification Chart: Phylum Cnidaria

Salient Features

Feature	Salient Features
Level of Organization	Tissue level; composed of distinct tissues but lack true organs.
Body Symmetry	Radial symmetry; body parts arranged around a central axis.
Body Forms	Two main body forms: polyp (sessile) and medusa (free-swimming).
Body Structure	Body consists of an outer epidermis and inner gastrodermis, with a gelatinous mesoglea in between.
Cnidocytes	Specialized stinging cells containing nematocysts used for defense and capturing prey.
Digestive System	Incomplete digestive system with a single opening serving as both mouth and anus, leading into the gastrovascular cavity. They have a central gastro-vascular cavity with a single opening, mouth on hypostome.
Nervous System	Simple nerve net without a central brain.
Reproduction	Both sexual and asexual reproduction. Those cnidarians which exist in both forms exhibit alternation of generation (Metagenesis), i.e., polyps produce medusae asexually and medusae form the polyps sexually (e.g., Obelia).
Lifecycle	Many cnidarians have complex life cycles involving both polyp and medusa stages.
Habitat	Mostly marine, with some freshwater species.
Ecological Role	Important in marine ecosystems; some form coral reefs that provide habitat for diverse marine life.

Watch The Video of Jelly Fish Here

Examples:

• Hydra (freshwater polyp),
• Aurelia (moon jellyfish),
• Physalia (Portuguese man o’ war),
• Acropora (stony coral)

Animal Kingdom Classification Chart: Phylum Ctenophora

Salient Features

Feature	Salient Features
Level of Organization	Tissue level; composed of distinct tissues but lack organs.
Body Symmetry	Biradial symmetry; exhibits symmetry along two axes.
Body Structure	Transparent, gelatinous body with eight rows of comb plates bearing comb-like cilia (ctenes) used for locomotion. The body bears eight external rows of ciliated comb plates, which help in locomotion
Bioluminescence	Many species exhibit bioluminescence, producing flashes of light.
Digestive System	Complete digestive system with a mouth and anus.
Nervous System	Nerve net with a statocyst (balance organ) and sensory structures called tentilla for prey capture.
Reproduction	Mostly hermaphroditic; some species reproduce asexually through fragmentation or budding.
Habitat	Primarily marine, found in pelagic zones (open ocean), often near the ocean surface.
Ecological Role	Important in marine ecosystems as predators and prey, and contribute to nutrient cycling.

Examples:

• Pleurobrachia (sea gooseberry),
• Mnemiopsis (comb jelly),
• Bolinopsis (sea walnut)

Animal Kingdom Classification Chart: Phylum Platyhelminthes

Salient Features

Feature	Salient Features
Level of Organization	Organ level; exhibit organ systems but lack a true body cavity (acoelomate).
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Flattened body with dorsoventral compression.
Digestive System	Incomplete digestive system with a single opening serving as both mouth and anus (in some species).
Nervous System	Primitive nerve cords and ganglia, lacking a centralized brain.
Reproductive Strategy	Mostly hermaphroditic, with some species exhibiting sexual reproduction, and a few reproducing asexually.
Regeneration	Remarkable regenerative abilities; capable of regrowing lost body parts.
Habitat	Found in a variety of habitats including freshwater, marine, and damp terrestrial environments.
Ecological Role	Play diverse roles as predators, scavengers, and parasites in various ecosystems.

Animal Kingdom Classification Chart is Here

Examples

• Planaria (freshwater flatworm),
• Taenia (tapeworm),
• Dugesia (planarian)

Animal Kingdom Classification Chart: Phylum Aschelminthes

Salient Features

Feature	Salient Features
Level of Organization	Organ level; exhibit organ systems but lack a true body cavity (pseudocoelomate).
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Cylindrical body with a tapered end; often covered with a protective cuticle.
Digestive System	Complete digestive system with separate mouth and anus. Alimentary canal is complete with a well developed muscular pharynx.
Nervous System	Ganglia (clusters of nerve cells) and nerve cords, but lack a centralized brain.
Reproductive Strategy	Sexes are separate (dioecious), i.e., males and females are distinct. Varied reproductive strategies including sexual and asexual reproduction.
Habitat	Found in diverse habitats including soil, freshwater, marine, and damp environments.
Ecological Role	Fulfill various ecological roles including decomposition, nutrient cycling, and as prey for predators.

Examples

• Caenorhabditis elegans (nematode),
• Trichinella spiralis (trichinosis worm),
• Ascaris lumbricoides (roundworm)

Animal Kingdom Classification Chart: Phylum Annelida

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; exhibit well-developed organ systems and possess a true body cavity (coelom).
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Segmented body with repeating units called segments or metameres. Aquatic annelids like Nereis possess lateral appendages, parapodia, which help in swimming.
Segmentation	Division of the body into distinct segments, each with its own set of muscles and nerves.
Body Cavity (Coelom)	Coelomate; possesses a true body cavity (coelom) completely lined with mesoderm.
Respiration	Respiration occurs through the body surface or specialized respiratory structures like gills or parapodia.
Circulatory System	Closed circulatory system with a dorsal and ventral blood vessel and lateral hearts in some species.
Excretory System	Nephridia (sing. nephridium) help in osmoregulation and excretion.
Nervous System	Well-developed nervous system with a pair of cerebral ganglia (brain) and a ventral nerve cord.
Reproduction	Most species are dioecious (separate sexes) and reproduce sexually; some exhibit asexual reproduction.
Habitat	Found in diverse habitats including marine, freshwater, and terrestrial environments.
Ecological Role	Fulfill various ecological roles including scavenging, predation, and serving as food for other organisms.

Examples

Earthworms (Lumbricus terrestris), Polychaetes (marine bristle worms), Leeches (Hirudo medicinalis)

Animal Kingdom Classification Chart: Phylum Arthropoda

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; exhibit well-developed organ systems and possess a true body cavity (coelom).
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Segmented body covered by an exoskeleton made of chitin, providing protection and support.
Segmentation	Body divided into distinct segments, each with its own pair of jointed appendages for movement.
Exoskeleton	External skeleton molted periodically to accommodate growth (ecdysis).
Respiration	Respiratory structures vary from gills, book lungs, tracheae, to simple diffusion through the body surface.
Circulatory System	Open circulatory system with a dorsal heart and hemocoel filled with hemolymph.
Excretory System	Excretion takes place through malpighian tubules.
Nervous System	Well-developed nervous system with a dorsal brain and a ventral nerve cord.
Sensory System	Sensory organs like antennae, eyes (compound and simple), statocysts or balancing organs are present.
Reproductive Strategy	Diverse reproductive strategies including sexual reproduction with internal fertilization and external fertilization.
Habitat	Found in diverse habitats including terrestrial, freshwater, marine, and even aerial environments.
Ecological Role	Fill various ecological niches including herbivores, carnivores, scavengers, and pollinators.

Examples

• Apis (Honey bee),
• Bombyx (Silkworm),
• Laccifer (Lac insect)

Animal Kingdom Classification Chart: Phylum Mollusca

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; exhibit well-developed organ systems and possess a true body cavity (coelom).
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Soft-bodied animals typically covered by a mantle that may secrete a protective shell made of calcium carbonate.
Shell Types	Shells may be univalve (one piece), bivalve (two pieces), or absent in some species.
Feeding Method	Various feeding methods including filter feeding, grazing, scavenging, and predation.
Radula	The radula is a rasping tongue-like organ used for feeding in most species.
Respiration	Respiration occurs through gills or body surface.
Circulatory System	Open circulatory system with a heart and hemocoel filled with hemolymph.
Nervous System	Well-developed nervous system with a pair of cerebral ganglia (brain) and a ventral nerve cord.
Reproductive Strategy	Mostly sexual reproduction with internal fertilization, but some species are hermaphroditic.
Habitat	Found in diverse habitats including marine, freshwater, and terrestrial environments.
Ecological Role	Fulfill various ecological roles including herbivores, carnivores, filter feeders, and scavengers.

Examples

• Pila (Apple snail),
• Pinctada (Pearl oyster),
• Sepia (Cuttlefish),
• Loligo (Squid),
• Octopus (Devil fish),
• Aplysia (Seahare),
• Dentalium (Tusk shell)
• Chaetopleura (Chiton)

Animal Kingdom Classification Chart: Phylum Echinodermata

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; exhibit well-developed organ systems and possess a true body cavity (coelom).
Body Symmetry	Mostly pentaradial symmetry; body parts arranged in multiples of five around a central axis.
Body Structure	Hard, spiny endoskeleton made of calcium carbonate plates called ossicles.
Water Vascular System	Water vascular system is a Network of water-filled canals used for locomotion, feeding, respiration, and sensory perception.
Tube Feet	Tube Feets are extendable structures used for locomotion, feeding, and attachment.
Respiration	Respiration occurs through diffusion across the body surface and papulae (skin gills).
Circulatory System	Open circulatory system with a water vascular system and a ring canal around the central disk.
Nervous System	Simple nerve ring and radial nerves, with no centralized brain.
Reproductive Strategy	Mostly sexual reproduction with external fertilization; some species exhibit regeneration and asexual reproduction.
Habitat	Primarily marine, found in all ocean depths from intertidal zones to abyssal depths.
Ecological Role	Fulfill various ecological roles including predators, scavengers, and ecosystem engineers.

Examples

• Asterias (Star fish),
• Echinus (Sea urchin),
• Antedon(Sea lily),
• Cucumaria (Sea cucumber),
• Ophiura (Brittle star)

Animal Kingdom Classification Chart: Phylum Hemichordata

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; exhibit well-developed organ systems and possess a true body cavity (coelom).
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Soft-bodied animals with a three-part body plan consisting of proboscis, collar, and trunk.
Proboscis	Anterior portion of the body used for feeding and burrowing.
Collar	Middle portion of the body containing structures involved in filter feeding and respiration.
Trunk	Posterior portion of the body containing most of the internal organs.
Gill Slits	Pharyngeal gill slits used for filter feeding and respiration.
Stomochord	Structure resembling a primitive notochord, providing support to the pharynx.
Nervous System	Simple nerve cord with ganglia, lacking a centralized brain.
Reproductive Strategy	Mostly sexual reproduction with external fertilization; some species exhibit asexual reproduction.
Habitat	Primarily marine, found in shallow coastal waters and ocean depths.
Ecological Role	Fulfill various ecological roles including filter feeders and scavengers.

Examples

• Acorn Worms (Balanoglossus),
• Pterobranchs (small, colonial organisms)

Animal Kingdom Classification Chart: Phylum Chordata

Salient Features

Animals belonging to the phylum Chordata are fundamentally characterized by the presence of a notochord, a dorsal hollow nerve cord, and paired pharyngeal gill slits.

They exhibit bilateral symmetry, are triploblastic, and coelomate with an organ-system level of organization. Additionally, they possess a post-anal tail and have a closed circulatory system.

Examples

• Human: Homo sapiens
• Domestic Dog: Canis lupus familiaris
• African Elephant: Loxodonta africana

Classification of Phylum Chordata

Subphylum	Salient Features	Examples
Urochordata or Tunicata	Notochord is present only in larval tail,	Ascidia, Salpa, Doliolum
Cephalochordata	Notochord extends from head to tail region and is persistent throughout their life.	Branchiostoma (Amphioxus or Lancelet)
Vertebrata	Notochord present during the embryonic period. The notochord is replaced by a cartilaginous or bony vertebral column in the adult. The ventral muscular heart with two, three or four chambers, kidneys for excretion and osmoregulation and paired appendages which may be fins or limbs present.	House Sparrow: Passer domesticus Bald Eagle: Haliaeetus leucocephalus Common Ostrich: Struthio camelus

Division of Vertebrata	Class
Agnatha (lacks jaw)	Cyclostomata
Gnathostomata (bears jaw)	Chondrichthyes Osteichthyes Amphibia Reptilia Aves Mammals

Animal Kingdom Classification Chart: Class Cyclostomata

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; possess a true body cavity (coelom) and a well-developed organ system.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Elongated, eel-like body with smooth, scaleless skin.
Skeleton	Cartilaginous skeleton, lacking jaws and paired fins.
Mouth	Circular, jawless mouth with keratinized teeth, adapted for suction and feeding on host’s body fluids.
Respiratory System	Multiple pairs of gill pouches for respiration.
Nervous System	Well-developed brain and sensory organs; simple vertebral column.
Reproductive Strategy	Mostly external fertilization; separate sexes; some species show a larval stage that undergoes metamorphosis.
Habitat	Marine and freshwater environments; some species are anadromous, migrating between salt and fresh water.
Feeding Habits	Parasitic or scavengers; feed on the blood and tissues of other fish or organic debris.
Ecological Role	Important in aquatic ecosystems as both predators and prey; play a role in nutrient cycling.

Examples

• Petromyzon marinus (Sea Lamprey),
• Myxine glutinosa (Atlantic Hagfish)

Animal Kingdom Classification Chart: Class Chondrichthyes

Salient Features

Features	Salient Features
Level of Organization	Organ system level; well-developed organ systems including circulatory, respiratory, and digestive systems.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Elongated, streamlined bodies with cartilaginous skeletons.
Skeleton	Made of cartilage, which is lighter and more flexible than bone.
Jaws and Teeth	Possess well-developed jaws with multiple rows of sharp, replaceable teeth.
Respiratory System	Gills for breathing, typically five to seven pairs of gill slits. . Gill slits are separate and without operculum (gill cover).
Skin	Covered with placoid scales (dermal denticles) that reduce friction while swimming.
Fins	Paired pectoral and pelvic fins, along with dorsal, anal, and caudal fins for stability and maneuverability.
Reproductive Strategy	Internal fertilization; some species are oviparous (egg-laying), ovoviviparous (egg-hatching within the mother), or viviparous (live-bearing).
Sensory Organs	Highly developed senses including vision, smell, and electroreception (Ampullae of Lorenzini). Some of them have electric organs (e.g., Torpedo) and some possess poison sting (e.g., Trygon). They are cold-blooded (poikilothermous) animals, i.e., they lack the capacity to regulate their body temperature.
Habitat	Mostly marine, with some species found in freshwater environments.
Ecological Role	Predators and scavengers, playing a crucial role in maintaining the balance of marine ecosystems.

Examples

• Carcharodon carcharias (Great White Shark),
• Sphyrna lewini (Scalloped Hammerhead),
• Raja clavata (Thornback Ray)

Animal Kingdom Classification Chart: Class Osteichthyes

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; highly developed organ systems including circulatory, respiratory, and digestive systems.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Varied body shapes, typically streamlined; covered with scales.
Skeleton	Bony skeleton made of calcified bones.
Jaws and Teeth	Well-developed jaws with fixed teeth; teeth are generally not replaceable.
Respiratory System	Gills covered by a bony operculum for breathing; typically have a swim bladder for buoyancy.
Skin	Covered with overlapping scales (ctenoid or cycloid) that provide protection and reduce friction.
Fins	Paired pectoral and pelvic fins, along with dorsal, anal, and caudal fins for stability and movement.
Reproductive Strategy	Mostly external fertilization; oviparous (egg-laying), with some species showing parental care.
Sensory Organs	Well-developed senses including vision, smell, and lateral line system for detecting vibrations.
Habitat	Found in various aquatic environments, both marine and freshwater.
Ecological Role	Key role in aquatic food webs; include both predators and prey species.

Examples

• Salmo salar (Atlantic Salmon),
• Amphiprion ocellaris (Clownfish),
• Gadus morhua (Atlantic Cod)

Animal Kingdom Classification Chart: Class Amphibia

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; well-developed organ systems including circulatory, respiratory, and digestive systems.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Typically have moist, smooth skin without scales; undergo metamorphosis from larval to adult stage. A tympanum represents the ear.
Respiratory System	Breathe through gills (larvae), lungs (adults), and skin (cutaneous respiration).
Heart	Three-chambered heart (two atria and one ventricle).
Limbs	Usually four limbs; some species may be limbless or have reduced limbs.
Reproduction	Mostly external fertilization; lay eggs in water or moist environments.
Development	Exhibit metamorphosis; aquatic larvae transform into terrestrial or semi-aquatic adults.
Habitat	Found in both aquatic and terrestrial environments; often near water bodies.
Skin	Moist, permeable skin that allows for cutaneous respiration and must remain moist to function properly.
Ecological Role	Important in food webs as both predators and prey; indicators of environmental health.

Examples

• Rana temporaria (Common Frog),
• Ambystoma mexicanum (Axolotl),
• Bufo bufo (Common Toad)

Animal Kingdom Classification Chart: Class Reptilia

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; highly developed organ systems including circulatory, respiratory, and digestive systems.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Dry, scaly skin; body covered with keratinized scales or scutes.
Respiratory System	Lungs for breathing; no cutaneous respiration.
Heart	Three-chambered heart (two atria and one ventricle) with partial separation; crocodilians have a four-chambered heart.
Temperature Regulation	Ectothermic (cold-blooded); rely on external heat sources to regulate body temperature.
Reproduction	Internal fertilization; mostly oviparous (egg-laying), with some ovoviviparous and viviparous species.
Development	Direct development; no larval stage.
Skin	Dry, impervious to water, with scales or scutes that prevent desiccation.
Limbs	Usually four limbs; some species (like snakes) are limbless.
Habitat	Occupy a wide range of habitats including deserts, forests, wetlands, and oceans.
Ecological Role	Important in food webs as predators and prey; help control pest populations.

Examples

• Alligator mississippiensis (American Alligator),
• Chelonia mydas (Green Sea Turtle),
• Varanus komodoensis (Komodo Dragon)

Animal Kingdom Classification Chart: Class Aves

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; highly developed organ systems including circulatory, respiratory, and digestive systems.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Covered in feathers; forelimbs modified into wings; lightweight skeleton with air sacs for efficient flight.
Respiratory System	Highly efficient respiratory system with air sacs; unidirectional airflow through the lungs.
Heart	Four-chambered heart with complete separation of oxygenated and deoxygenated blood.
Temperature Regulation	Endothermic (warm-blooded); able to regulate body temperature internally.
Reproduction	Internal fertilization; oviparous (egg-laying); hard-shelled eggs with amniotic membranes.
Development	Embryonic development within the egg; precocial or altricial young.
Feeding	Varied diet including seeds, fruits, insects, fish, and small mammals; specialized beaks for different feeding habits.
Habitat	Occupy diverse habitats including forests, grasslands, wetlands, and aquatic environments.
Ecological Role	Important in ecosystems as pollinators, seed dispersers, predators, and prey.

Examples

• Passer domesticus (House Sparrow),
• Haliaeetus leucocephalus (Bald Eagle),
• Struthio camelus (Ostrich)

Animal Kingdom Classification Chart: Class Mammalia

Salient Features

Feature	Salient Features
Level of Organization	Organ system level; highly developed organ systems including circulatory, respiratory, and digestive systems.
Body Symmetry	Bilateral symmetry; body can be divided into two equal halves along a single plane.
Body Structure	Covered in hair or fur; mammary glands for milk production; endothermic (warm-blooded).
Respiratory System	Lungs for breathing; diaphragm separates thoracic and abdominal cavities.
Heart	Four-chambered heart with complete separation of oxygenated and deoxygenated blood.
Temperature Regulation	Endothermic (warm-blooded); able to regulate body temperature internally.
Reproduction	Internal fertilization; viviparous (live-bearing) or oviparous (egg-laying); young nourished with milk from mammary glands.
Development	Viviparous species give birth to live young; young undergo maternal care and suckling.
Feeding	Varied diet including herbivores, carnivores, and omnivores; specialized teeth for different feeding habits.
Habitat	Occupy diverse habitats including forests, grasslands, deserts, and aquatic environments.
Ecological Role	Important in ecosystems as predators, prey, seed dispersers, and ecosystem engineers.

Examples

• Homo sapiens (Human),
• Canis lupus familiaris (Dog),
• Felis catus (Domestic Cat)

Differences Between Chordate and Nonchordate:

Feature	Chordates or vertebrates	Non-Chordates or invertebrates
Notochord	Present at least during embryonic development; may persist in some adults.	Absent throughout life cycle.
Dorsal Nerve Cord	Present, located dorsal to the notochord, usually hollow.	Absent or ventral nerve cord present.
Pharyngeal Slits	Present at some stage of life, used for respiration or filter-feeding.	Absent or present only in some non-chordate groups for feeding or respiration.
Post-anal Tail	Present at some stage of life, may be lost during development in some species.	Absent in most species.
Endostyle or Thyroid Gland	Present in some, functioning as a filter-feeding structure or thyroid gland.	Absent or different structures for similar functions.
Segmentation	Present in some chordates, especially in the embryo; absent in most adults.	Present in some non-chordate groups, such as Annelids and Arthropods.
Body Symmetry	Bilateral symmetry, though exceptions exist.	May exhibit bilateral, radial, or no symmetry.
Body Cavity (Coelom)	Coelomates; possess a true body cavity derived from mesoderm.	Non-coelomates or pseudocoelomates; lack a true body cavity or have a derived cavity.
Skeleton	Endoskeleton made of cartilage or bone in most species.	Exoskeleton (e.g., shells), hydrostatic skeleton, or absent skeleton.
Respiratory Organs	Gills, lungs, or both; may exhibit cutaneous respiration in some amphibians.	Gills, tracheae, book lungs, or diffusion through the body surface.
Examples	Fishes, amphibians, reptiles, birds, mammals.	Porifera, Cnidaria, Platyhelminthes, Annelida, Mollusca, Arthropoda, etc.

The animal kingdom classification chart provides a systematic framework for understanding the vast diversity of life on Earth. Through this hierarchical arrangement, scientists can organize and categorize animals based on shared characteristics, evolutionary relationships, and anatomical features.

FAQ:

The National Eligibility cum Entrance Test (NEET) is a highly competitive examination in India for aspiring medical and dental students. Among the three core subjects, Biology holds immense significance, comprising 50% of the total marks. In this article will provide a comprehensive overview of the NEET Biology syllabus, covering the essential concepts and topics that students must focus on to excel in the examination.

The Table Outlining The NEET Biology syllabus

The NEET Biology syllabus for Class 11:

Unit	Topics
Unit 1: Diversity in the Living World	Introduction to Biology, Classification of Living Organisms, Plant Kingdom, Animal Kingdom
Unit 2: Structural Organization in Plants and Animals	Morphology of Flowering Plants, Anatomy of Flowering Plants, Animal Tissues
Unit 3: Cell Structure and Function	Cell Structure, Cell Organelles, Biomolecules, Cell Cycle and Cell Division
Unit 4: Plant Physiology	Transport in Plants, Mineral Nutrition, Photosynthesis, Respiration
Unit 5: Human Physiology	Digestive System, Respiratory System, Circulatory System, Excretory System, Nervous System

The NEET Biology syllabus for Class 12:

Unit	Topics
Unit 6: Reproduction	Reproduction in Organisms, Sexual Reproduction in Flowering Plants, Human Reproduction, Reproductive Health
Unit 7: Genetics and Evolution	Principles of Inheritance, Molecular Basis of Inheritance, Evolution, Human Health and Diseases
Unit 8: Biology and Human Welfare	Human Health and Diseases, Microbes in Human Welfare, Biotechnology, Strategies for Enhancement in Food Production
Unit 9: Biotechnology and Its Applications	Principles and Processes, Applications in Medicine and Agriculture
Unit 10: Ecology and Environment	Organisms and Populations, Ecosystem, Biodiversity and Conservation, Environmental Issues

Detailed NEET Biology Syllabus For Class 11

Chapter-1: The Living World

What is living? Biodiversity; Need for classification; three domains of life; taxonomy and systematics; concept of species and taxonomical hierarchy; binomial nomenclature; tools for study of taxonomy- museums, zoological parks, herbaria, botanical gardens.

Let’s Visualize The Chapter

Chapter-2: Biological Classification

Five kingdom classification; Salient features and classification of Monera, Protista and Fungi into major groups: Lichens, Viruses and Viroids.

Let’s Visualize The Chapter

Chapter-3: Plant Kingdom

Salient features and classification of plants into major groups – Algae, Bryophyta, Pteridophyta, Gymnospermae and Angiospermae (three to five salient and distinguishing features and at least two examples of each category); Angiosperms – classification upto class, characteristic features and examples.

Chapter-4: Animal Kingdom

Salient features and classification of animals, non-chordates up to phyla level, and chordates up to class level (three to five salient features and at least two examples of each category).

Chapter-5: Morphology of Flowering Plants

Morphology and modifications: Morphology of different parts of flowering plants: root, stem, leaf, inflorescence, flower, fruit.

Chapter-6: Anatomy of Flowering Plants

Plants Anatomy and functions of different tissues and tissue systems.

Chapter-7: Structural Organization in Animals

Animal tissues; Morphology, anatomy and functions of different systems (digestive, circulatory, respiratory, nervous and reproductive) of an insect (cockroach).

Chapter-8: Cell-The Unit of Life

Cell theory and cell as the basic unit of life: Structure of prokaryotic and eukaryotic cells; Plant cell and animal cell; cell envelope; cell membrane, cell wall; cell organelles – structure and function; endomembrane system, endoplasmic reticulum, golgi bodies, lysosomes, vacuoles; mitochondria, ribosomes, plastids, microbodies; cytoskeleton, cilia, flagella, centrioles (ultrastructure and function); nucleus.

Chapter-9: Biomolecules

Chemical constituents of living cells: biomolecules, structure and function of proteins, carbohydrates, lipids, nucleic acids; Enzymes- types, properties, enzyme action.

Chapter-10: Cell Cycle and Cell Division

Cell cycle, mitosis, meiosis and their significance

Chapter-11: Transport in Plants

Movement of water, gases and nutrients; cell to cell transport, diffusion, facilitated diffusion, active transport; plant-water relations, imbibition, water potential, osmosis, plasmolysis; long distance transport of water – Absorption, apoplast, symplast, transpiration pull, root pressure and guttation; transpiration, opening and closing of stomata; Uptake and translocation of mineral nutrients – Transport of food, phloem transport, mass flow hypothesis.

Chapter-12: Mineral Nutrition

Essential minerals, macro- and micronutrients and their role; deficiency symptoms; mineral toxicity; elementary idea of hydroponics as a method to study mineral nutrition; nitrogen metabolism, nitrogen cycle, biological nitrogen fixation.

Chapter-13: Photosynthesis in Higher Plants

Photosynthesis as a means of autotrophic nutrition; site of photosynthesis, pigments involved in photosynthesis (elementary idea); photochemical and biosynthetic phases of photosynthesis; cyclic and non-cyclic photophosphorylation; chemiosmotic hypothesis; photorespiration; C3 and C4 pathways; factors affecting photosynthesis.

Chapter-14: Respiration in Plants

Exchange of gases; cellular respiration – glycolysis, fermentation (anaerobic), TCA cycle and electron transport system (aerobic); energy relations – number of ATP molecules generated; amphibolic pathways; respiratory quotient.

Chapter-15: Plant – Growth and Development

Seed germination; phases of plant growth and plant growth rate; conditions of growth; differentiation, dedifferentiation, and re-differentiation; sequence of developmental processes in a plant cell; growth regulators – auxin, gibberellin, cytokinin, ethylene, ABA; seed dormancy; vernalization; photoperiodism.

Chapter-16: Digestion and Absorption

Alimentary canal and digestive glands, role of digestive enzymes and gastrointestinal hormones; Peristalsis, digestion, absorption and assimilation of proteins, carbohydrates and fats; calorific values of proteins, carbohydrates and fats; egestion; nutritional and digestive disorders – PEM, indigestion, constipation, vomiting, jaundice, diarrhoea.

Chapter-17: Breathing and Exchange of Gases

Respiratory organs in animals (recall only); Respiratory system in humans; mechanism of breathing and its regulation in humans – exchange of gases, transport of gases and regulation of respiration, respiratory volume; disorders related to respiration – asthma, emphysema, occupational respiratory disorders.

Chapter-18: Body Fluids and Circulation

Composition of blood, blood groups, coagulation of blood; composition of lymph and its function; human circulatory system – Structure of human heart and blood vessels; cardiac cycle, cardiac output, ECG; double circulation; regulation of cardiac activity; disorders of circulatory system – hypertension, coronary artery disease, angina pectoris, heart failure.

Chapter-19: Excretory Products and Their Elimination

Modes of excretion – ammonotelism, ureotelism, uricotelism; human excretory system – structure and function; urine formation, osmoregulation; regulation of kidney function – renin – angiotensin, atrial natriuretic factor, ADH and diabetes insipidus; role of other organs in excretion; disorders – uraemia, renal failure, renal calculi, nephritis; dialysis and artificial kidney, kidney transplant.

Chapter-20: Locomotion and Movement

Types of movement – ciliary, flagellar, muscular; skeletal muscle- contractile proteins and muscle contraction; skeletal system and its functions; joints; disorders of muscular and skeletal system – myasthenia gravis, tetany, muscular dystrophy, arthritis, osteoporosis, gout.

Chapter-21: Neural Control and Coordination

Neuron and nerves; Nervous system in humans – central nervous system; peripheral nervous system and visceral nervous system; generation and conduction of nerve impulse; reflex action; sensory perception; sense organs; elementary structure and functions of eye and ear.

Chapter-22: Chemical Coordination and Integration

Endocrine glands and hormones; human endocrine system – hypothalamus, pituitary, pineal, thyroid, parathyroid, adrenal, pancreas, gonads; mechanism of hormone action (elementary idea); role of hormones as messengers and regulators, hypo – and hyperactivity and related disorders; dwarfism, acromegaly, cretinism, goiter, exophthalmic goiter, diabetes, Addison’s disease.

NEET Biology Syllabus For Class 12

Chapter-23: Reproduction in Organisms

Reproduction, a characteristic feature of all organisms for continuation of species; modes of reproduction – asexual and sexual reproduction; asexual reproduction – binary fission, sporulation, budding, gemmule formation, fragmentation; vegetative propagation in plants.

Chapter-24: Sexual Reproduction in Flowering Plants

Flower structure; development of male and female gametophytes; pollination – types, agencies and examples; outbreeding devices; pollen-pistil interaction; double fertilization; post fertilization events – development of endosperm and embryo, development of seed and formation of fruit; special modes- apomixis, parthenocarpy, polyembryony; Significance of seed dispersal and fruit formation.

Chapter-25: Human Reproduction

Male and female reproductive systems; microscopic anatomy of testis and ovary; gametogenesis – spermatogenesis and oogenesis; menstrual cycle; fertilization, embryo development up to blastocyst formation, implantation; pregnancy and placenta formation (elementary idea); parturition (elementary idea); lactation (elementary idea).

Chapter-26: Reproductive Health

Need for reproductive health and prevention of Sexually Transmitted Diseases (STDs); birth control – need and methods, contraception and medical termination of pregnancy (MTP); amniocentesis; infertility and assisted reproductive technologies – IVF, ZIFT, GIFT (Elementary idea for general awareness).

Chapter-27: Principles of Inheritance and Variation

Heredity and variation: Mendelian inheritance; deviations from Mendelism – incomplete dominance, co- dominance, multiple alleles and inheritance of blood groups, pleiotropy; elementary idea of polygenic inheritance; chromosome theory of inheritance; chromosomes and genes; Sex determination – in humans, birds and honey bee; linkage and crossing over; sex linked inheritance – haemophilia, colour blindness; Mendelian disorders in humans -thalassemia; chromosomal disorders in humans; Down’s syndrome, Turner’s and Klinefelter’s syndromes.

Chapter-28: Molecular Basis of Inheritance

Search for genetic material and DNA as genetic material; Structure of DNA and RNA; DNA packaging; DNA replication; Central dogma; transcription, genetic code, translation; gene expression and regulation. – lac operon; genome and human and rice genome projects; DNA fingerprinting.

Chapter-29: Evolution

Origin of life; biological evolution and evidences for biological evolution (paleontology, comparative anatomy, embryology and molecular evidences); Darwin’s contribution, modern synthetic theory of evolution; mechanism of evolution – variation (mutation and recombination) and natural selection with examples, types of natural selection; Gene flow and genetic drift; Hardy – Weinberg’s principle; adaptive radiation; human evolution.

Chapter-30: Human Health and Diseases

Pathogens; parasites causing human diseases (malaria, dengue, chickengunia, filariasis, ascariasis, typhoid, pneumonia, common cold, amoebiasis, ring worm) and their control; Basic concepts of immunology – vaccines; cancer, HIV and AIDS; Adolescence – drug and alcohol abuse.

Chapter-31: Strategies for Enhancement in Food Production

Improvement in food production: Plant breeding, tissue culture, single cell protein, Biofortification, Apiculture and Animal husbandry.

Chapter-32: Microbes in Human Welfare

In household food processing, industrial production, sewage treatment, energy generation and microbes as bio-control agents and bio-fertilizers. Antibiotics; production and judicious use.

Chapter-33: Biotechnology

Principles and processes Genetic Engineering (Recombinant DNA Technology).

Chapter-34: Biotechnology and its Application

Application of biotechnology in health and agriculture: Human insulin and vaccine production, stem cell technology, gene therapy; genetically modified organisms – Bt crops; transgenic animals; biosafety issues, bio piracy and patents.

Chapter-35: Organisms and Populations

Organisms and environment: Habitat and niche, population and ecological adaptations; population interactions – mutualism, competition, predation, parasitism; population attributes – growth, birth rate and death rate, age distribution.

Chapter-36: Ecosystem

Ecosystems: Patterns, components; productivity and decomposition; energy flow; pyramids of number, biomass, energy; nutrient cycles (carbon and phosphorous); ecological succession; ecological services – carbon fixation, pollination, seed dispersal, oxygen release (in brief).

Chapter-37: Biodiversity and its Conservation

Biodiversity-Concept, patterns, importance; loss of biodiversity; biodiversity conservation; hotspots, endangered organisms, extinction, Red Data Book, biosphere reserves, national parks, sanctuaries and Ramsar sites.

Chapter-38: Environmental Issues

Air pollution and its control; water pollution and its control; agrochemicals and their effects; solid waste management; radioactive waste management; greenhouse effect and climate change impact and mitigation; ozone layer depletion; deforestation; any one case study as success story addressing the environmental issue(s).

Disclaimer: This NEET Biology syllabus, separating the topics covered in Class 11 and Class 12. It’s important to note that this is a general representation, and the specific topics and subtopics may vary. It’s always advisable to refer to the official NEET syllabus or study materials provided by the exam conducting authority for the most accurate and up-to-date information.

Tips For The Neet Students To Study The Neet Biology Syllabus

Here are some tips for effective biology preparation for NEET:

1. Understand the concepts: Focus on understanding the concepts rather than rote memorization.
2. Read NCERT textbooks: Start with NCERT textbooks to build a strong foundation.
3. Make notes: Prepare concise notes while studying to review important points quickly.
4. Practice questions: Solve a variety of questions from different sources, including previous year question papers and mock tests.
5. Revise regularly: Regular revision is essential to retain the learned information.
6. Use visual aids: Utilize diagrams, flowcharts, and mnemonics to aid in memorization.
7. Seek clarification: If you have doubts or confusion, seek help from teachers, peers, or online resources.

A strong grasp of the NEET Biology syllabus is crucial for students aiming to pursue medical and dental courses in India. This article has provided a comprehensive overview of the essential concepts and topics covered in the NEET Biology syllabus. By thoroughly understanding and studying these concepts, aspiring students will be better prepared to excel in the NEET examination and embark on a successful career in the medical field. Remember to refer to official NEET syllabus documents and reliable study materials for in-depth understanding and accurate preparation. Best of luck!

Frequently Asked Questions(FAQ) on Neet Biology Syllabus:

In life on Earth, every organism, from the tiniest microbe to the mightiest mammal, is intricately interconnected. How do we organize and categorize them? The answer lies in biological classification taxonomy. Biological classification, also known as taxonomy, organizes living organisms into hierarchical groups based on shared characteristics.

Definition of Biological Classification Taxonomy:

• Biological classification taxonomy is a scientific discipline concerned with organizing and categorizing living organisms based on their shared characteristics and evolutionary relationships. It provides a systematic framework for naming, classifying, and studying the vast diversity of life forms on Earth.
• Through biological classification taxonomy, organisms are grouped into hierarchical categories, from the most specific (species) to the most general (kingdom), allowing scientists to understand and communicate about the relationships between different species and groups.
• This biological classification taxonomy system helps researchers uncover patterns of evolutionary history, biodiversity, and ecological interactions, ultimately contributing to our understanding of the natural world.

If you want to know about the first chapter, then read the article: The Living World – Full Chapter Here.

Biological Classification Taxonomy of Five Kingdom Classification:

Characters	Monera	Protista	Fungi	Plantae	Animalia
Cell Type	Prokaryotic	Eukaryotic	Eukaryotic	Eukaryotic	Eukaryotic
Cell Wall	Noncellulosic (Polysaccharide amino acid)	Present in some	Present with chitin	Present (cellulose)	Absent
Nuclear Membrane	Absent	Present	Present	Present	Present
Body organization	Cellular	Cellular	Multiceullar/ loose tissue	Tissue/ organ	Tissue/organ/ organ system
Mode of nutrition	Autotrophic (chemosynthetic and photosynthetic) and Heterotrophic (saprophytic/parasitic)	Autotrophic (Photosynthetic) and Heterotrophic	Heterotrophic (Saprophytic/ Parasitic)	Autotrophic (Photosynthetic)	Heterotrophic (Holozoic/ Saprophytic etc.)
Examples	Bacteria (e.g., Escherichia coli, Bacillus subtilis) Archaea (e.g., Methanogens, Halophiles)	Amoeba (e.g., Amoeba proteus) Euglena (e.g., Euglena gracilis) Paramecium (e.g., Paramecium caudatum) Diatoms (e.g., Navicula, Cyclotella)	Mushrooms (e.g., button mushrooms, chanterelles) Yeasts (e.g., Saccharomyces cerevisiae) Molds (e.g., Penicillium, Aspergillus) Lichens (symbiotic organisms consisting of fungi and algae or cyanobacteria)	Trees (e.g., oak, pine, maple) Flowers (e.g., roses, sunflowers, tulips) Grasses (e.g., wheat, rice, corn) Ferns (e.g., maidenhair fern, Boston fern)	Humans (Homo sapiens sapiens) Lions (Panthera leo) Dogs (Canis lupus familiaris) Insects (e.g., bees, ants, butterflies)

Get the detail NEET Biology Syllabus Here.

The Biomolecules chapter is Here

Salient Features and Classification of Monera:

In biological classification taxonomy, Monera is one of the five kingdoms of biological classification, encompassing a diverse group of organisms that are characterized by their simple cellular structure and prokaryotic nature. These organisms play crucial roles in various ecosystems, from the decomposition of organic matter to nitrogen fixation.

Salient Features:

1. Prokaryotic Cells: Monera are comprised of prokaryotic cells, which lack a true nucleus and membrane-bound organelles. Instead, their genetic material is contained within a single circular chromosome, typically located in the nucleoid region of the cell.
2. Cellular Structure: Monerans exhibit a wide range of cellular morphologies, including cocci (spherical), bacilli (rod-shaped), and spirilla (spiral-shaped). Some species may also form colonies or filaments.
3. Cell Wall Composition: The cell wall of Monera is primarily composed of peptidoglycan, a unique polysaccharide structure that provides structural support and protection to the cell. However, some species may lack a cell wall entirely.
4. Metabolism: Monerans display diverse metabolic capabilities, including autotrophic and heterotrophic modes of nutrition. Autotrophic species can synthesize their own organic molecules from inorganic sources, while heterotrophic species rely on organic compounds for energy and carbon.
5. Reproduction: Monerans reproduce asexually through binary fission, where a single cell divides into two identical daughter cells. Some species may also exchange genetic material through processes such as conjugation, transformation, or transduction.

Classification:

In biological classification taxonomy, the classification of Monera is primarily based on genetic, biochemical, and morphological characteristics. Traditionally, Monera has been divided into two main groups:

1. Bacteria (Eubacteria): Bacteria are the most abundant and diverse group of Monerans, inhabiting virtually every environment on Earth. They exhibit a wide range of metabolic diversity, including aerobic and anaerobic respiration, nitrogen fixation, and fermentation. Bacteria are further classified based on their shape, staining characteristics (Gram-positive or Gram-negative), and metabolic properties.
2. Archaea (Archaebacteria): Archaea are ancient prokaryotic organisms that thrive in extreme environments such as hot springs, salt flats, and deep-sea hydrothermal vents. They exhibit unique biochemical and genetic features distinct from bacteria and are classified into multiple phyla based on phylogenetic analysis.

Recent advancements in molecular biology and genomics have led to revisions in the classification of Monera, with ongoing efforts to elucidate the evolutionary relationships and diversity within this kingdom. New techniques such as metagenomics, which involve the sequencing of environmental DNA, are providing insights into the vast diversity of microbial life on Earth.

Salient Features and Classification of Protista:

In biological classification taxonomy, Protista is a diverse kingdom of eukaryotic organisms that includes a wide variety of unicellular, colonial, and multicellular organisms. These organisms exhibit a range of morphological, physiological, and ecological characteristics, making them essential components of various ecosystems.

Salient Features:

1. Eukaryotic Cells: Protists are characterized by the presence of eukaryotic cells, which contain membrane-bound organelles including a true nucleus. This distinguishes them from prokaryotic organisms, such as bacteria and archaea.
2. Cellular Diversity: Protists exhibit a wide range of cellular morphologies, including spherical (coccoid), rod-shaped (bacillar), spiral (spirillar), and amoeboid shapes. Some protists may form colonies or multicellular structures.
3. Nutritional Modes: Protists display diverse modes of nutrition, including autotrophic, heterotrophic, and mixotrophic strategies. Autotrophic protists, such as algae, can photosynthesize to produce their own food, while heterotrophic protists obtain nutrients by ingesting organic matter. Mixotrophic protists exhibit a combination of autotrophic and heterotrophic characteristics.
4. Habitats: Protists inhabit a wide range of aquatic and terrestrial environments, including freshwater and marine habitats, soil, and symbiotic relationships with other organisms. Some protists are free-living, while others are parasitic or symbiotic.
5. Reproduction: Protists reproduce through a variety of mechanisms, including binary fission, multiple fission, budding, fragmentation, and sexual reproduction. Many protists have complex life cycles involving both sexual and asexual phases.

Classification:

In biological classification taxonomy, Protists are a diverse and polyphyletic group, meaning they do not share a common ancestor and are instead classified based on evolutionary relationships inferred from molecular, morphological, and ecological data. The classification of protists is constantly evolving as new information becomes available. However, protists are traditionally grouped into several major taxonomic groups:

1. Algae: Algae are photosynthetic protists that can range from unicellular to multicellular forms. They are found in diverse habitats, including freshwater, marine environments, and moist terrestrial habitats. Examples include diatoms, dinoflagellates, green algae, brown algae, and red algae.
2. Protozoa: Protozoa are heterotrophic protists that obtain nutrients by ingesting organic matter. They exhibit a wide range of morphologies and locomotion mechanisms, including flagella, cilia, and pseudopodia. Examples include amoebas, paramecia, euglenas, and ciliates.
3. Slime Molds: Slime molds are protists that exhibit both unicellular and multicellular stages in their life cycles. They are often found in damp, decaying organic matter and play important roles in decomposition and nutrient cycling.
4. Water Molds: Water molds, or oomycetes, are protists that resemble fungi in their filamentous morphology and mode of nutrition. They are often found in aquatic environments and are important decomposers and pathogens of plants and animals.
5. Other Groups: In addition to the major taxonomic groups mentioned above, protists include a diverse array of organisms with unique characteristics and ecological roles. These may include colonial protists, mixotrophic organisms, and symbiotic associations such as lichens.

Salient Features and Classification of Fungi:

In biological classification taxonomy, Fungi constitute a diverse kingdom of eukaryotic organisms that play critical roles in ecosystems as decomposers, symbionts, and pathogens. They exhibit unique morphological, physiological, and ecological characteristics, making them distinct from other kingdoms of life.

Salient Features:

1. Eukaryotic Cells: Fungi are composed of eukaryotic cells, meaning they have a true nucleus and membrane-bound organelles such as mitochondria and Golgi apparatus. This distinguishes them from prokaryotic organisms like bacteria.
2. Heterotrophic Nutrition: Fungi are heterotrophs, meaning they obtain their nutrients by absorbing organic matter from their environment. They secrete enzymes that break down complex organic molecules into simpler forms, which are then absorbed through their cell walls.
3. Cell Wall Composition: Fungi have cell walls primarily composed of chitin, a complex polysaccharide that provides structural support and protection. This sets them apart from other eukaryotic organisms, such as plants and animals, which have cell walls made of cellulose or other materials.
4. Morphological Diversity: Fungi exhibit a wide range of morphologies, including multicellular filamentous structures called hyphae, which collectively form a network known as mycelium. Some fungi produce specialized reproductive structures such as mushrooms, while others exist as yeasts or single-celled forms.
5. Reproduction: Fungi reproduce through a combination of sexual and asexual means. Sexual reproduction involves the fusion of specialized reproductive structures called gametes, while asexual reproduction occurs through the production of spores, which are dispersed and germinate to form new fungal colonies.

Classification:

In biological classification taxonomy, the Fungi are classified into several major taxonomic groups based on their morphological characteristics, reproductive strategies, and genetic relationships. The classification of fungi is complex and continues to evolve with advances in molecular biology and phylogenetics. However, the major taxonomic groups include:

1. Phylum Zygomycota: Zygomycetes are characterized by their production of thick-walled resting structures called zygospores, which result from the fusion of specialized hyphae. They include bread molds and other saprophytic fungi.
2. Phylum Ascomycota: Ascomycetes, or sac fungi, produce sexual spores called ascospores within sac-like structures called asci. They include diverse organisms such as yeasts, molds, truffles, and morels.
3. Phylum Basidiomycota: Basidiomycetes, or club fungi, produce sexual spores called basidiospores on specialized club-shaped structures called basidia. They include mushrooms, puffballs, rusts, and smuts.
4. Phylum Glomeromycota: Glomeromycetes form arbuscular mycorrhizal symbioses with the roots of most terrestrial plants, playing essential roles in nutrient uptake and plant health.
5. Phylum Chytridiomycota: Chytrids are aquatic or soil-dwelling fungi characterized by their flagellated reproductive cells. Some chytrid species are parasites of plants, algae, or animals, while others are saprobes.
6. Phylum Mycetozoa: Mycetozoans, or slime molds, are unique fungi that exhibit both animal-like and fungus-like characteristics. They include plasmodial slime molds and cellular slime molds.

Let’s Visualize The Chapter Biological Classification Taxonomy

Kingdom Plantae:

• In biological classification taxonomy, the kingdom Plantae encompasses all eukaryotic organisms containing chlorophyll, commonly referred to as plants.
• Some members of this kingdom exhibit partial heterotrophy, such as insectivorous plants or parasites. Examples of insectivorous plants include bladderwort and Venus flytrap, while Cuscuta serves as a parasite.
• Plant cells display a eukaryotic structure characterized by prominent chloroplasts and a cell wall primarily composed of cellulose.
• Plantae comprises algae, bryophytes, pteridophytes, gymnosperms, and angiosperms.
• The life cycle of plants involves two distinct phases: the diploid sporophytic and the haploid gametophytic phases, which alternate with each other.
• The duration of these phases and whether they are independent or reliant on other organisms vary among different plant groups. This phenomenon is known as alternation of generations.

Kingdom Animalia:

• In biological classification taxonomy, this kingdom comprises multicellular heterotrophic eukaryotic organisms whose cells lack cell walls.
• They rely directly or indirectly on plants for sustenance, digesting their food internally and storing reserves as glycogen or fat.
• Their nutritional mode is holozoic, involving the ingestion of food.
• These organisms follow a defined growth pattern, reaching adulthood with distinct shapes and sizes.
• Higher forms exhibit sophisticated sensory and neuromotor mechanisms, with many capable of locomotion.
• Sexual reproduction in this kingdom occurs through the copulation of male and female individuals, followed by embryonic development.

Lichens, Viruses, and Viroids:

In this living world, there exist microorganisms that defy conventional classification and challenge our understanding of biological diversity. Lichens, viruses, and viroids are three such entities that hold profound significance in ecology, medicine, and molecular biology.

Lichens

Lichens are remarkable organisms that often go unnoticed in the natural world, yet they play crucial roles in various ecosystems and have captivated scientists and nature enthusiasts alike for centuries. In this article, we will delve into the salient features and classification of lichens, shedding light on their fascinating biology and diversity.

Salient Features of Lichens:

1. Symbiotic Nature: One of the most distinctive features of lichens is their symbiotic relationship between a fungus (the mycobiont) and a photosynthetic partner (the photobiont), typically green algae or cyanobacteria. This symbiosis allows lichens to thrive in a wide range of environments, from barren deserts to harsh polar regions.
2. Thallus Structure: Lichens exhibit a variety of growth forms, collectively known as thalli, which can range from crustose (crust-like) to foliose (leaf-like) and fruticose (shrub-like). These growth forms are adapted to different environmental conditions and play important roles in nutrient acquisition, water retention, and reproduction.
3. Environmental Tolerance: Lichens are known for their remarkable tolerance to extreme environmental conditions, including drought, high levels of ultraviolet radiation, and pollution. They are often the first organisms to colonize bare rock or soil, initiating the process of primary succession in ecosystems.
4. Chemical Defense: Lichens produce a variety of secondary metabolites, including pigments, acids, and antibiotics, which serve as chemical defenses against herbivores, pathogens, and competing organisms. These compounds also contribute to the diverse colors and textures observed in lichens.
5. Reproductive Strategies: Lichens reproduce through a combination of sexual and asexual means. Sexual reproduction involves the formation of fungal spores or algal cells, which can fuse to form a new lichen thallus. Asexual reproduction occurs through fragmentation, where portions of the thallus break off and establish new colonies.

Classification of Lichens:

Lichens are classified based on the dominant fungal partner (the mycobiont) and the growth form of the thallus. The most common groups of lichens include:

1. Crustose Lichens: These lichens have a crust-like thallus that is tightly attached to the substrate, such as rocks or bark. Examples include species of the genera Lecanora and Caloplaca.
2. Foliose Lichens: Foliose lichens have a leaf-like thallus with distinct upper and lower surfaces. They are often loosely attached to the substrate and can be easily detached. Examples include species of the genera Parmelia and Lobaria.
3. Fruticose Lichens: Fruticose lichens have a shrub-like or branching thallus that is typically erect or pendant. These lichens can be found growing on soil, rocks, or other substrates. Examples include species of the genera Usnea and Cladonia.
4. Squamulose Lichens: Squamulose lichens have a thallus composed of small, scale-like structures called squamules. They are often found growing on soil or rocks in arid or semi-arid environments. Examples include species of the genera Psora and Cladia.

Ecological Significance:

Lichens play vital roles in ecosystems as pioneers in primary succession, contributing to soil formation, nitrogen fixation, and habitat creation. They serve as food sources for a variety of organisms, including insects, birds, and mammals, and are important indicators of environmental health and air quality.

Examples of Lichens:

1. Reindeer Lichen (Cladonia rangiferina): Found in Arctic and subarctic regions, this lichen forms dense mats resembling reindeer antlers. It is an important food source for caribou and reindeer during harsh winters.
2. British Soldier Lichen (Cladonia cristatella): Named for its red caps resembling British soldiers’ uniforms, this lichen is commonly found on tree bark and rocks in forests across North America.
3. Old Man’s Beard (Usnea spp.): This distinctive lichen hangs from tree branches like grayish-green beards, giving it its common name. It is found in various habitats worldwide and is used in traditional medicine.
4. Pixie Cup Lichen (Cladonia pyxidata): Recognizable by its cup-shaped fruiting bodies, this lichen grows on soil, rocks, and tree bark in forests and heathlands. It is widespread across Europe and North America.
5. Powdered Sunshine Lichen (Xanthoria spp.): This bright yellow or orange lichen is commonly found on rocks, tree bark, and man-made structures in sunny, exposed habitats. It is tolerant of pollution and is often used as an indicator of air quality.

Viruses

Viruses are fascinating microorganisms that straddle the line between living and non-living entities. Despite their simplicity, they wield immense power in shaping ecosystems and influencing the course of life on Earth.

Salient Features of Viruses:

1. Submicroscopic Size: Viruses are incredibly small, ranging in size from 20 to 300 nanometers. They are not visible under a light microscope and require specialized techniques such as electron microscopy for visualization.
2. Genetic Material: Viruses contain genetic material, either DNA or RNA, surrounded by a protein coat called a capsid. Some viruses also possess additional structures such as an envelope derived from the host cell membrane.
3. Host Dependence: Viruses are obligate intracellular parasites, meaning they can only replicate inside host cells. They lack the cellular machinery necessary for metabolism and reproduction and must hijack the host cell’s machinery to replicate.
4. Diverse Shapes: Viruses exhibit a wide range of shapes, including helical, icosahedral, and complex structures. Their morphology is determined by the arrangement of viral proteins and genetic material within the capsid.
5. Modes of Transmission: Viruses employ diverse strategies for transmission, including direct contact, respiratory droplets, fecal-oral route, and vector-borne transmission by arthropods. Understanding the mechanisms of viral transmission is crucial for controlling and preventing viral outbreaks.

Classification of Viruses:

Viruses are classified based on various criteria, including their genetic material, structure, mode of replication, and host specificity. The International Committee on Taxonomy of Viruses (ICTV) classifies viruses into several orders, families, genera, and species. Common taxonomic groups of viruses include:

1. DNA Viruses: These viruses contain DNA as their genetic material and include families such as Herpesviridae, Adenoviridae, and Papillomaviridae.
2. RNA Viruses: RNA viruses contain RNA as their genetic material and are further classified into positive-sense RNA viruses (e.g., Picornaviridae, Flaviviridae), negative-sense RNA viruses (e.g., Paramyxoviridae, Orthomyxoviridae), and double-stranded RNA viruses (e.g., Reoviridae).
3. Retroviruses: Retroviruses contain RNA as their genetic material but replicate through a reverse transcription process to produce DNA. Examples include Human Immunodeficiency Virus (HIV) and Human T-cell Leukemia Virus (HTLV).

Examples of Viruses:

1. Influenza Virus: The influenza virus belongs to the Orthomyxoviridae family and is responsible for seasonal flu outbreaks worldwide. It exhibits high mutation rates, leading to the emergence of new strains and the need for annual vaccination.
2. Human Immunodeficiency Virus (HIV): HIV is a retrovirus that causes Acquired Immunodeficiency Syndrome (AIDS), a condition characterized by the progressive weakening of the immune system. Despite advances in treatment, HIV/AIDS remains a significant global health challenge.
3. Herpes Simplex Virus (HSV): HSV belongs to the Herpesviridae family and is responsible for oral and genital herpes infections. It establishes latent infections in nerve cells, leading to recurrent outbreaks of painful sores.
4. Hepatitis B Virus (HBV): HBV is a DNA virus that infects the liver, causing acute and chronic hepatitis. It is transmitted through contact with infected blood or bodily fluids and can lead to severe liver damage, including cirrhosis and liver cancer.
5. Ebola Virus: Ebola virus belongs to the Filoviridae family and causes severe hemorrhagic fever in humans and non-human primates. It is transmitted through direct contact with infected bodily fluids and has a high mortality rate during outbreaks.

Viroids

Viroids are intriguing entities in the realm of microbiology, representing a unique group of infectious agents with a minimalistic structure and significant implications for plant health and agriculture.

Salient Features of Viroids:

1. Minimalistic Structure: Viroids are small, circular RNA molecules that lack a protein coat (capsid). They typically range in size from a few hundred to over a thousand nucleotides and are among the smallest infectious agents known to science.
2. No Protein Coding Capacity: Unlike viruses, viroids do not encode any proteins and rely entirely on host cellular machinery for replication and propagation. They contain a single-stranded RNA genome that folds into complex secondary structures critical for their biological activity.
3. Pathogenic Potential: Viroids are pathogens of plants, causing a variety of diseases characterized by stunting, leaf curling, yellowing, and necrosis. They infect a wide range of plant species, including crop plants such as potatoes, tomatoes, citrus, and avocado, leading to significant economic losses in agriculture.
4. Mechanism of Infection: Viroids enter plant cells through wounds or natural openings and replicate in the nucleus or chloroplasts using host enzymes. They induce changes in gene expression, disrupt cellular processes, and trigger immune responses in infected plants.

Classification of Viroids:

Viroids are classified into two families based on their structure, sequence homology, and host range:

1. Pospiviroidae: This family includes viroids with a rod-like secondary structure and conserved central regions. Examples of pospiviroids include Potato spindle tuber viroid (PSTVd) and Tomato chlorotic dwarf viroid (TCDVd).
2. Avsunviroidae: Avsunviroids have a branched secondary structure with conserved central regions and variable terminal regions. The type species in this family is Avocado sunblotch viroid (ASBVd).

Examples of Viroids:

1. Potato Spindle Tuber Viroid (PSTVd): PSTVd is one of the best-characterized viroids and causes spindle tuber disease in potatoes. It is transmitted through infected tubers and leads to reduced yields and tuber quality.
2. Citrus Exocortis Viroid (CEVd): CEVd infects citrus trees and is responsible for citrus exocortis disease, characterized by stunted growth, bark scaling, and reduced fruit yield. It is transmitted through grafting and mechanical contact.
3. Tomato Chlorotic Dwarf Viroid (TCDVd): TCDVd infects tomato plants and causes chlorotic dwarfism, leaf curling, and reduced fruit size. It is transmitted through mechanical contact and seed transmission.
4. Apple Scar Skin Viroid (ASSVd): ASSVd infects apple trees and leads to the development of scarred lesions on fruit skins, reducing their marketability. It is transmitted through infected budwood and grafting.
5. Hop Stunt Viroid (HSVd): HSVd infects hop plants and causes stunting, chlorosis, and reduction in cone production. It is transmitted through infected plant material and contributes to economic losses in the hop industry.

The biological classification taxonomy serves as a foundational tool in our exploration and understanding of the intricate web of life on Earth. By systematically organizing and categorizing living organisms based on their shared characteristics and evolutionary relationships, taxonomy provides a roadmap for navigating the complexities of biodiversity.

FAQ on Biological Classification Taxonomy:

Biology is an important subject of science because it helps us to know the human body and gives information about its structure and function. As most complex biological terminology is provided in abbreviated form, it is necessary to understand the biology full forms properly.
In the study of biology, abbreviations are more frequently used to name species systems or mechanisms. Here is the list of several biology full forms:

List of Important Biology Full Forms

Sl. No.	Abbreviations	Biology Full Forms
1	AC	Adenylate Cyclase
2	ADH	Vasopressin/Anti-diuretic Hormone
3	AIDS	Acquired Immuno Deficiency Syndrome
4	ANF	Atrial-Natriuretic factor
5	ACTH	Adreno Corticotrophic Hormone
6	AML	Acute Myeloid Leukemia
7	BAC	Bacterial Artificial Chromosome
8	BP	Blood Pressure
9	BPPI	Biophysics of Proteins and Protein Interactions
10	BOD	Biochemical oxygen Demand
11	Bt	Bacillus thuringiensis
12	BCG	Bacillus Calmette-Guerin
13	BMD	Bone Mineral Density
14	BMI	Body Mass Index
15	CCK	Cholecystokinin
16	COA	Coenzyme A
17	CFCs	Chloro-fluro-carbons
18	CMI	Cell – Mediated Immunity
19	CNG	Compressed Natural Gas
20	CFT	Complement Fixation Test
21	CDK	Cyclin-dependent kinase
22	CSF	Cerebrospinal Fluid
23	CMV	Cytomegalovirus
24	CPR	Cardio-Pulmonary Resuscitation
25	DFC	Detritus food chain
26	DU	Dobson Unit
27	dB	Decibel
28	DNA	Deoxyribonucleic Acid
29	DAP	Diamine phosphate
30	DVT	Deep Vein Thrombosis
31	2, 4-D	2, 4-Dichlorophenoxy acetic acid
32	DOTS	Directly Observed Therapy
33	ECG	Electrocardiogram
34	EEG	Electroencephalogram
35	ETC	Electron Transport Chain
36	ELISA	Enzyme Linked Immuno Sorbent Assay
37	ENT	Ear Nose Throat
38	GFR	Glomerular Filtration Rate
39	GH	Growth Hormone
40	GnRH	Gonadotrophin Releasing Hormone
41	GA3	Gibberellic acid
42	GIFT	Gamete Intra-fallopian transfer
43	GMO	Genetically modified Organisms
44	GPP	Gross Primary Productivity
45	GFC	Grazing food chain
46	HIV	Human Immunodeficiency Viruses
47	hCG	Human Chorionic Gonadotrophin
48	hPL	Human Placental Lactogen
49	HGP	Human Genome Project
50	hnRNA	Heterogeneous Nuclear RNA
51	IUCN	International Union for Conservation of Nature & Natural Resources
52	ICU	Intensive Care Unit
53	IG	Immunoglobulin
54	IUD	Intrauterine devices
55	IUI	Intra Uterine Insemination
56	ICSI	Intra cytoplasmic sperm injection
57	IUT	Intra Uterine Transfer
58	IMR	Infant Mortality Rate
59	ITP	Idiopathic Thrombocytopenic Purpura
60	IUDs	Intra Uterine Devices
61	IVF	In-vitro fertilization
62	ICBN	International Code for Botanical Nomenclature
63	ICZN	International Code of Zoological Nomenclature
64	JGA	Juxta-Glomerular Apparatus
65	KVIC	Khadi & Village Industries Commission
66	LHC	Light Harvesting Complex
67	LAB	Lactic Acid Bacteria
68	MAP	Microtubule-associated protein
69	MC	Menstrual Cycle
70	MMC	Megaspore mother cell
71	MMR	Maternal Mortality Rate
72	MTP	Medical Termination of Pregnancy
73	MSH	Melanocyte Stimulating Hormone
74	MRI	Magnetic Resonance Imaging
75	MOET	Multiple Ovulation Embryo Transfer Technology
76	MALT	Mucosal Associated Lymphoid Tissue
77	MMR	Measles, Mumps and Rubella
78	MHD	Magneto hydrodynamics
79	NAD	Nicotinamide Adenine Dinucleotide (Coenzyme)
80	NAA	Napthalene Acetic Acid
81	NHC	Non-histone Chromosomal proteins
82	NPP	Net Primary Productivity
83	OCD	Obsessive Compulsive Disorder
84	OAA	Oxalo acetic acid
85	Ori	Origin of Replication
86	OPD	Outpatient Department
87	ppm	Parts per million
88	PTH	Parathyroid hormone
89	PGA	Phosphoglyceric acid
90	PPLO	Pleuro Pneumonia Like Organisms
91	PGRS	Plant Growth Regulators
92	PMC	Pollen mother cell/microscope mother cell.
93	PEN	Primary Endosperm Nucleus
94	PCR	Polymerase Chain Reaction
95	ppb	Parts per billion
96	RuBisCO	Ribulose bisphosphate carboxylase-oxygenase
97	RQ	Respiratory Quotient
98	RTI	Reproductive Tract Infection
99	RBC	Red Blood Cell
100	RTA	Renal Tubular Acidosis
101	RNA	Ribonucleic Acid
102	RO	Reverse Osmosis
103	snRNA	Small Nuclear RNA
104	sRNA	Soluble RNA
105	STDS	Sexually Transmitted Diseases
106	SCP	Single Cell Protein
107	STPs	Sewage Treatment Plants
108	SGOT	Serum Glutamic Oxaloacetic Transaminase
109	SGPT	Serum Glutamic Pyruvic Transaminase
110	TT	Tetanus Toxoid
111	Ti Plasmid	Tumor Inducing Plasmid
112	Taq	Thermus aquaticus
113	TSH	Thyroid Stimulating Hormone
114	T3	Triodothyronine
115	T4	Tetraiodothyronine or thyroxine
116	TCT	Thyrocalcitonin.
117	VNTR	Variable Number of Tandem Repeats
118	WBC	White Blood Cell
119	WHO	World Health Organization
120	YAC	Yeast Artificial Chromosome
121	ZIFT	Zygote Intra-fallopian transfer

Definition Of Each Biology Full Forms

1. AC: Adenylate Cyclase-

Among the important biology full forms the first one is Adenylate cyclase, is an essential enzyme found in various organisms, including humans. It plays a crucial role in cellular signaling by catalyzing the conversion of adenosine triphosphate (ATP) into cyclic adenosine monophosphate (cAMP). This reaction is known as cyclization.

2. ADH: Vasopressin/Anti-diuretic Hormone-

Vasopressin, also known as antidiuretic hormone (ADH), is a peptide hormone produced by the hypothalamus and released by the posterior pituitary gland. It plays a vital role in regulating water balance and blood pressure in the body. The primary function of vasopressin is to reduce the excretion of water by the kidneys, thereby conserving water in the body and concentrating urine.

3. AIDS : Acquired Immuno Deficiency Syndrome-

Acquired Immune Deficiency Syndrome (AIDS), is a severe and advanced stage of infection with the Human Immunodeficiency Virus (HIV). HIV is a retrovirus that attacks the immune system, specifically targeting CD4+ T cells, which are crucial in mounting an effective immune response against infections. Over time, the continuous destruction of these cells weakens the immune system, making the person vulnerable to opportunistic infections and certain cancers.

4. ANF: Atrial-Natriuretic factor-

Atrial Natriuretic Peptide (ANP), also known as Atrial Natriuretic Factor (ANF), is a hormone produced primarily by the atria of the heart. It plays a vital role in regulating blood pressure and fluid balance in the body. ANP is released in response to increased stretching of the atrial walls, which occurs when there is an increase in blood volume or pressure in the heart’s chambers.

5. ACTH: Adreno Corticotrophic Hormone-

Adrenocorticotropic hormone (ACTH), also known as corticotropin, is a hormone produced by the anterior pituitary gland in the brain. It plays a crucial role in the regulation of the body’s response to stress and the control of cortisol production in the adrenal glands.

6. AML: Acute Myeloid Leukemia-

Acute Myeloid Leukemia (AML), is a type of cancer that affects the bone marrow and blood. It is characterized by the rapid growth of abnormal myeloid cells, which are immature white blood cells that would normally develop into various types of mature blood cells (e.g., red blood cells, platelets, and other types of white blood cells).

7. BAC: Bacterial Artificial Chromosome-

Bacterial Artificial Chromosome (BAC), is a type of vector used in molecular biology and genetics to clone and manipulate large DNA fragments, including entire genes or even whole genomes. BACs are widely used tools in genomics research, as they allow scientists to study and analyze the genetic material of organisms, including humans, animals, and plants.

8. BP: Blood Pressure-

Blood pressure refers to the force exerted by the blood against the walls of the arteries as it is pumped by the heart. It is a crucial physiological parameter that indicates the pressure within the circulatory system and is essential for maintaining adequate blood flow to various organs and tissues in the body.

9. BPPI: Biophysics of Proteins and Protein Interactions-

Biophysics, which is the interdisciplinary field that combines principles of physics and biology to study biological processes and structures at the molecular level. It plays a crucial role in understanding the biophysical properties of proteins and their interactions, which are fundamental to the functioning of living organisms. Related to this biology full forms, you can read more about proteins in this article: Relationship Between Protein Structure and Function | Structure and Function of Proteins.

10. BOD : Biochemical oxygen Demand-

Biochemical Oxygen Demand (BOD) is a critical water quality parameter used to measure the level of organic pollution in water bodies. It is a measure of the amount of dissolved oxygen (DO) required by microorganisms to break down organic material present in the water through aerobic biological processes.

11. Bt: Bacillus thuringiensis-

Bacillus thuringiensis (Bt), is a gram-positive, spore-forming bacterium that is widely known for its insecticidal properties. It is an important natural biological control agent used in agriculture and forestry to combat certain insect pests. Bt produces a variety of protein toxins known as “delta-endotoxins” or “Cry toxins,” which are specifically toxic to certain groups of insects but generally harmless to humans, animals, and beneficial insects.

12. BCG: Bacillus Calmette-Guerin-

Bacillus Calmette-Guerin (BCG), is a live attenuated vaccine derived from the Mycobacterium bovis bacterium. It is used primarily as a vaccine against tuberculosis (TB) and is one of the most widely administered vaccines worldwide. The BCG vaccine is named after its developers, Albert Calmette and Camille Guerin, who developed it in the early 20th century.

13. BMD: Bone Mineral Density-

Bone mineral density (BMD), is a measure of the amount of minerals, primarily calcium and phosphorus, present in a specific volume of bone tissue. It is an essential parameter used to assess bone health and diagnose conditions such as osteoporosis and osteopenia.

14. BMI: Body Mass Index-

Body Mass Index (BMI), is a numerical value derived from an individual’s weight and height, used to categorize their body composition and assess whether their weight falls within a healthy range. It is a widely used tool to evaluate whether a person is underweight, normal weight, overweight, or obese, and it provides a quick and easy way to estimate body fat and associated health risks.

15. CCK: Cholecystokinin-

Cholecystokinin (CCK), is a hormone and neuropeptide that plays a crucial role in the digestive system and the regulation of appetite. It is produced by cells in the lining of the small intestine and released in response to the presence of fats and proteins in the digestive tract.

16. COA: Coenzyme A-

Coenzyme A (CoA), is a small, water-soluble molecule that plays a crucial role in various metabolic processes within cells. It acts as a coenzyme, which means it works together with specific enzymes to facilitate chemical reactions in the cell. Coenzyme A is essential for the metabolism of carbohydrates, fatty acids, and amino acids.

17. CFCs : Chlorofluorocarbons-

Chlorofluorocarbons (CFCs) are synthetic compounds composed of carbon, chlorine, and fluorine atoms. They belong to a family of halocarbon gases that were widely used in various industrial and consumer applications, especially as refrigerants, aerosol propellants, and foam-blowing agents.

18. CMI : Cell – Mediated Immunity-

Cell-mediated immunity, also known as cellular immunity, is a critical component of the immune response that involves the activation of specific immune cells to defend the body against intracellular pathogens, such as viruses, certain bacteria, and parasites. This type of immunity is distinct from humoral immunity, which involves the production of antibodies by B cells to neutralize extracellular pathogens.

19. CNG: Compressed Natural Gas-

Compressed Natural Gas (CNG), is a clean and environmentally friendly alternative to traditional fossil fuels like gasoline and diesel. It is a gaseous form of natural gas composed mainly of methane (CH4) that is compressed to a high pressure to increase its energy density and storage capacity. CNG is primarily used as a fuel for vehicles, especially in the transportation sector, due to its lower emissions and cost-effectiveness.

20. CFT: Complement Fixation Test-

Complement Fixation Test (CFT), is a serological laboratory technique used to detect the presence of specific antibodies in a patient’s blood against a particular pathogen or antigen. It is based on the principle of complement activation, a component of the immune system that helps destroy foreign pathogens.

21. CDK: Cyclin-dependent kinase-

Cyclin-dependent kinases (CDKs), are a family of enzymes that play a crucial role in regulating the cell cycle. They are a group of protein kinases that function as key regulators of cell cycle progression by controlling the activities of other proteins through phosphorylation. The cell cycle is a tightly controlled process that governs cell growth and division, ensuring the accurate duplication and segregation of genetic material during cell division.

22. CSF: Cerebrospinal Fluid-

Cerebrospinal fluid (CSF), is a clear, colorless fluid that surrounds the brain and spinal cord within the central nervous system (CNS). It is one of the essential components of the CNS, playing several vital roles in protecting and supporting the brain and spinal cord.

23. CMV: Cytomegalovirus-

Cytomegalovirus (CMV), is a common virus that belongs to the herpesvirus family. It is a widespread virus that can infect people of all ages, and once infected, the virus remains in the body for life. In healthy individuals, CMV infections are usually asymptomatic or cause mild flu-like symptoms. However, CMV can cause more severe complications in individuals with weakened immune systems or in certain groups, such as newborns and pregnant women.

24. CPR: Cardio-Pulmonary Resuscitation-

Cardio-Pulmonary Resuscitation (CPR), is an emergency procedure performed to revive a person whose heart has stopped beating or is experiencing a life-threatening cardiac or respiratory event. The goal of CPR is to restore blood circulation and oxygen supply to vital organs, especially the brain, until professional medical help can arrive.

25. DFC : Detritus food chain-

Detritus food chain, also known as the decomposer food chain or detrital food chain, is a type of food chain that begins with dead organic matter and involves the decomposition and breakdown of this material by detritivores and decomposers. Unlike traditional food chains that start with producers (plants) and move up to consumers (herbivores and carnivores), the detritus food chain starts with non-living organic matter.

26. DU: Dobson Units-

Dobson Units (DU), are a unit of measurement used to quantify the concentration of ozone in the Earth’s atmosphere. They are named after G.M.B. Dobson, a British scientist who was instrumental in pioneering ozone research. Dobson Units are commonly used in atmospheric science and meteorology to express the thickness or concentration of ozone in a vertical column of air.

27. dB: Decibel-

The decibel (dB) is a logarithmic unit of measurement used to express the ratio of two values, typically of a physical quantity, relative to a specific reference level. It is widely used in various fields, including acoustics, electronics, telecommunications, and physics. The decibel scale is particularly useful when dealing with large ranges of values and when comparing quantities that span many orders of magnitude.

28. DNA: Deoxyribonucleic Acid-

One of the most used biology full forms is Deoxyribonucleic Acid, commonly known as DNA, which is a molecule that contains the genetic instructions essential for the growth, development, functioning, and reproduction of all known living organisms and many viruses. DNA is a double-stranded, helical structure and serves as the blueprint or code for the synthesis of proteins and other molecules necessary for life.

29. DAP: Diamine phosphate-

“Diamine phosphate” is not a specific and recognized chemical compound. It seems to be a combination of two terms: “diamine” and “phosphate.

30. DVT: Deep Vein Thrombosis-

Deep Vein Thrombosis (DVT), is a medical condition characterized by the formation of a blood clot (thrombus) in a deep vein, usually in the legs. It is a serious condition that requires prompt medical attention as it can lead to potentially life-threatening complications if left untreated.

31. 2, 4-D : 2, 4-Dichlorophenoxy acetic acid-

2,4-Dichlorophenoxyacetic acid (2,4-D), is a synthetic herbicide and plant growth regulator widely used in agriculture, horticulture, and forestry to control broadleaf weeds in crops and non-crop areas. It is one of the most extensively used herbicides in the world and has been in use since the 1940s.

32. DOTS: Directly Observed Therapy-

Directly Observed Therapy (DOT), is a tuberculosis (TB) control strategy used to ensure that patients with TB adhere to their prescribed treatment regimen. TB is a bacterial infection caused by Mycobacterium tuberculosis and primarily affects the lungs. To effectively treat TB and prevent the development of drug-resistant strains, it is crucial that patients complete their full course of treatment.

33. EEG: Electrocardiogram-

One of the generally used biology full forms is ECG captures the electrical impulses generated by the heart as it contracts and relaxes. This process is orchestrated by a specialized group of cells within the heart known as the sinoatrial node (SA node), often referred to as the heart’s natural pacemaker. The SA node initiates each heartbeat by sending an electrical signal that spreads throughout the atria, causing them to contract and push blood into the ventricles. Subsequently, the signal is transmitted to the atrioventricular node (AV node), which delays it slightly before relaying it to the ventricles, ensuring proper coordination of atrial and ventricular contractions.

34. ETC : Electron Transport Chain-

Electron Transport Chain (ETC), is a crucial process that takes place in the inner mitochondrial membrane of eukaryotic cells (or the plasma membrane of prokaryotic cells) during cellular respiration. It is the final stage of aerobic respiration, where electrons derived from the breakdown of fuel molecules (such as glucose) are transferred through a series of protein complexes, ultimately leading to the production of adenosine triphosphate (ATP), the cell’s primary energy currency.

35. ELISA : Enzyme Linked Immuno Sorbent Assay-

Enzyme-Linked Immunosorbent Assay, commonly known as ELISA, is a highly sensitive and widely used laboratory technique for detecting and measuring the presence of specific proteins, antibodies, or antigens in a sample. ELISA is a fundamental tool in immunology, clinical diagnostics, and biomedical research.

36. EEG: Electroencephalogram-

Electroencephalogram, commonly referred to as an EEG, is a diagnostic test used to measure and record the electrical activity of the brain. It is a non-invasive procedure that helps doctors and healthcare professionals understand the brain’s functioning by monitoring the electrical signals produced by neurons.

37.ENT: Ear Nose Throat-

Ear, Nose, and Throat (ENT), is a medical specialty that focuses on the diagnosis and treatment of conditions related to the ears, nose, throat, and related structures of the head and neck. ENT specialists, also known as otolaryngologists, are medical doctors who have completed specialized training in this field.

38. GFR: Glomerular Filtration Rate-

One of the important biology full forms is the Glomerular Filtration Rate (GFR), which is a critical measure used in nephrology (the study of the kidneys) to assess how well the kidneys are functioning in filtering waste and excess substances from the blood. GFR is considered one of the most important indicators of kidney function and is used in the diagnosis and monitoring of various kidney diseases and conditions.

39. GH: Growth Hormone-

Growth Hormone (GH), also known as human growth hormone (HGH) or somatotropin, is a peptide hormone produced by the pituitary gland, a small gland located at the base of the brain. It plays a crucial role in stimulating growth, cell reproduction, and regeneration in the body.

40. GnRH : Gonadotrophin Releasing Hormone-

Gonadotropin-Releasing Hormone (GnRH), also known as Gonadotropin-Releasing Hormone or Luteinizing Hormone-Releasing Hormone (LHRH), is a crucial hormone produced by the hypothalamus, a region in the brain. It plays a fundamental role in the regulation of reproductive function in both males and females by controlling the release of two important pituitary hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

41. GA3: Gibberellic acid-

Gibberellic acid (GA), is a naturally occurring plant hormone that belongs to the gibberellin family. It plays a crucial role in regulating various aspects of plant growth and development, particularly in promoting stem elongation, seed germination, flowering, and fruit development. Gibberellins were initially discovered as a result of their association with a plant disease known as “foolish seedling,” caused by the fungus Gibberella fujikuroi.

42.GIFT: Gamete Intra-fallopian transfer-

Gamete intra-fallopian transfer (GIFT), is an assisted reproductive technology (ART) procedure used to treat infertility in couples who have difficulty conceiving naturally. GIFT is a variation of in vitro fertilization (IVF) that involves the transfer of both eggs (oocytes) and sperm into the woman’s fallopian tubes, where fertilization can take place naturally.

43. GMO : Genetically modified Organisms-

In biotechnology one of the most used biology full forms is Genetically Modified Organisms (GMOs), which are living organisms whose genetic material has been altered using genetic engineering techniques. This modification involves the introduction of specific genes from one organism (source) into the DNA of another organism (target) to confer desirable traits or characteristics. GMOs can include plants, animals, microorganisms, and even some insects.

44. GPP: Gross Primary Productivity-

One of the most used biology full forms is Gross Primary Productivity (GPP), is a critical ecological term that represents the total amount of energy captured by plants in an ecosystem through photosynthesis over a specific period, typically measured in units of energy per unit area per unit time (e.g., kJ/m²/year or g/m²/day). GPP is one of the essential components used to quantify the flow of energy through ecosystems and serves as the foundation for all higher trophic levels in the food chain.

45. GFC: Grazing food chain-

Grazing food chain, also known as the grazing trophic pathway, is a type of ecological food chain that represents the flow of energy and nutrients through an ecosystem starting from the primary producers and progressing through successive trophic levels. In a grazing food chain, energy is transferred from plants (primary producers) to herbivores (primary consumers), and then to carnivores (secondary and higher-order consumers) as they consume one another.

46.HIV: Human Immunodeficiency Viruses-

Human Immunodeficiency Viruses (HIV), which are a group of retroviruses that attack the human immune system, leading to a condition called Acquired Immunodeficiency Syndrome (AIDS). HIV is a global health concern and has led to millions of deaths worldwide since its discovery in the 1980s.

47. hCG: Human Chorionic Gonadotrophin-

Human Chorionic Gonadotropin (hCG), is a hormone produced by the placenta during pregnancy. It plays a crucial role in supporting early pregnancy and is commonly used as a marker in pregnancy tests to detect pregnancy.

48. hPL: Human Placental Lactogen-

One of the biology full forms is Human Placental Lactogen (hPL), also known as human chorionic somatomammotropin (HCS), is a hormone produced by the placenta during pregnancy. It belongs to the somatotropin family of hormones, which includes growth hormone and prolactin. hPL is essential for supporting pregnancy and plays various roles in maternal and fetal physiology.

49. HGP: Human Genome Project-

Human Genome Project (HGP) was an international scientific research effort that aimed to map and sequence the entire human genome. It was one of the most significant and ambitious scientific endeavors of the 20th century and early 21st century. The HGP provided foundational knowledge about the structure and organization of human genes, laying the groundwork for various advancements in genetics, medicine, and biotechnology.

50. hnRNA: Heterogeneous Nuclear RNA-

Heterogeneous Nuclear RNA (hnRNA), is an intermediate form of RNA that is synthesized during gene expression and processing within the cell nucleus. It serves as a precursor to mature messenger RNA (mRNA), which ultimately carries the genetic information from the DNA to the ribosomes in the cytoplasm for protein synthesis.

51. IUCN : International Union for Conservation of Nature & Natural Resources-

IUCN was founded in 1948 and was initially known as the International Union for the Protection of Nature (IUPN). It later changed its name to the International Union for Conservation of Nature and Natural Resources, and eventually to the current name, the International Union for Conservation of Nature.

52. ICU: Intensive Care Unit-

One of the medically used biology full forms is the Intensive Care Unit (ICU), which is a specialized department within a hospital that provides intensive and critical medical care to patients with life-threatening or severe medical conditions. The ICU is equipped with advanced medical technology and staffed by a highly trained healthcare team that includes intensivists (physicians specialized in critical care), nurses, respiratory therapists, and other specialists.

53. IG: Immunoglobulin-

Immunoglobulins, also known as antibodies, are essential components of the immune system that play a crucial role in defending the body against infections and foreign invaders. They are Y-shaped proteins produced by specialized immune cells called B lymphocytes (B cells) in response to the presence of antigens, which are specific molecules found on the surface of pathogens such as bacteria, viruses, and other foreign substances.

54. IUD: Intrauterine devices-

One of the important biology full forms is Intrauterine devices (IUDs) are a form of long-acting and reversible contraception that is inserted into the uterus to prevent pregnancy. They are small, T-shaped devices made of plastic, copper, or a combination of both materials. IUDs are highly effective, convenient, and provide protection against pregnancy for several years, depending on the type of IUD.

55. IUI: Intra Uterine Insemination-

Intrauterine Insemination (IUI), also known as artificial insemination, is an assisted reproductive technique used to facilitate pregnancy in couples experiencing difficulty conceiving naturally. During IUI, specially prepared sperm is directly introduced into the woman’s uterus, increasing the chances of sperm reaching the fallopian tubes and fertilizing the egg.

56. ICSI : Intra cytoplasmic sperm injection-

In reproductive biology, one of the important biology full forms is Intracytoplasmic Sperm Injection (ICSI), which is an advanced assisted reproductive technique used to treat male infertility when there are severe sperm-related issues. ICSI is performed as part of in vitro fertilization (IVF) and involves the direct injection of a single sperm into an egg to achieve fertilization.

57. IUT: Intra Uterine Transfer-

“Intra Uterine Transfer of sperm” might refer to the process of “Intrauterine Insemination” (IUI). Intrauterine insemination (IUI) is a fertility treatment in which sperm is directly placed into a woman’s uterus to enhance the chances of fertilization.

58. IMR : Infant Mortality Rate-

Infant mortality rate (IMR), is a critical demographic indicator that measures the number of deaths of infants under one year of age per 1,000 live births in a given population during a specific time period. It is often used as an important measure of a country’s or region’s overall health and well-being, as well as the quality of healthcare and socio-economic conditions.

59. ITP: Idiopathic Thrombocytopenic Purpura-

Idiopathic Thrombocytopenic Purpura (ITP), also known as Immune Thrombocytopenic Purpura, is a blood disorder characterized by a low platelet count (thrombocytopenia) due to the immune system mistakenly attacking and destroying platelets. Platelets are crucial blood cells involved in clotting and preventing bleeding. When the platelet count is significantly reduced, it can lead to a tendency for easy bruising and bleeding.

60. IUDs : Intra Uterine Devices-

Intrauterine Devices (IUDs), which are small, T-shaped contraceptive devices that are inserted into the uterus to prevent pregnancy. They are highly effective, long-acting, and reversible forms of birth control. IUDs work by affecting sperm movement, egg fertilization, and implantation of a fertilized egg.

61. IVF: In-vitro fertilization-

in the field of infertility one of the most used biology full forms is In-vitro fertilization (IVF) which is a reproductive technology and assisted reproductive technique that helps couples who are struggling with infertility to conceive a child. The process involves combining eggs and sperm outside the woman’s body in a laboratory, and then transferring the resulting embryo(s) into the woman’s uterus. IVF is one of the most effective methods of assisted reproduction and has helped millions of couples worldwide to achieve pregnancy and have children.

62. ICBN: International Code for Botanical Nomenclature-

International Code of Nomenclature for Algae, Fungi, and Plants (ICN), which is the set of rules and recommendations governing the scientific naming of algae, fungi, and plants. It is commonly referred to as the Botanical Code. The ICN is maintained and updated by the International Botanical Congress, which convenes every six years to discuss and amend the code if necessary.

63. ICZN: International Code of Zoological Nomenclature-

International Code of Zoological Nomenclature (ICZN), is a set of rules and principles that govern the scientific naming of animals. It provides a standardized system for naming new animal species and higher taxonomic groups, ensuring stability and consistency in zoological taxonomy. The ICZN is maintained and updated by the International Commission on Zoological Nomenclature (ICZN), an international body of zoologists.

64. JGA: Juxta-Glomerular Apparatus-

Juxtaglomerular apparatus (JGA), is a specialized structure found in the kidneys, specifically located at the point where the distal convoluted tubule (DCT) comes into close contact with the afferent arteriole of the same nephron. The JGA plays a crucial role in regulating blood pressure and kidney function through the renin-angiotensin-aldosterone system (RAAS).

65. KVIC: Khadi & Village Industries Commission-

In the field of biology one of the commercially used biology full forms is the Khadi and Village Industries Commission (KVIC), which is an autonomous body established by the Government of India to promote and develop Khadi and village industries in rural areas. It was founded on 2nd October 1956, as per the provisions of the Khadi and Village Industries Commission Act, 1956.

66. LHC : Light Harvesting Complex-

In botany one of the most used biology full forms is the Light Harvesting Complex (LHC), which is a crucial component of photosynthetic organisms, including plants, algae, and certain bacteria. It is a group of proteins and pigment molecules that work together to capture and transfer light energy during the process of photosynthesis. The primary function of the LHC is to absorb light energy and funnel it to the reaction centers of photosystems, where the energy is converted into chemical energy in the form of adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH).

67. LAB : Lactic Acid Bacteria-

Lactic acid bacteria (LAB), are a group of beneficial and diverse bacteria that produce lactic acid as the primary fermentation product from carbohydrates. They play essential roles in various food fermentation processes, probiotics, and other industrial applications. Lactic acid bacteria are gram-positive, non-spore-forming, and predominantly found in various environments, including the digestive tract of humans and animals, plants, and fermented foods.

68. MAP:  Microtubule-associated protein

Microtubule-associated proteins (MAPs) are a group of proteins that interact with microtubules, which are a component of the cytoskeleton in cells. The cytoskeleton is a dynamic network of protein filaments that provides structural support, maintains cell shape, facilitates cell division, and enables intracellular transport and movement.

69. MC: Menstrual Cycle-

Menstrual Cycle is a natural, recurring process that occurs in the female reproductive system. It involves a series of physiological changes and hormonal fluctuations that prepare the body for potential pregnancy each month. The menstrual cycle typically lasts about 28 days, although it can vary in length for different individuals.

70. MMC: Megaspore mother cell-

Megaspore mother cell, also known as the megasporocyte, is a specialized cell found in the ovule of seed plants. It plays a critical role in the process of megasporogenesis, which leads to the production of megaspores. Megasporogenesis is a part of the female reproductive process in seed plants and is essential for sexual reproduction.

71. MMR: Maternal Mortality Rate-

Maternal mortality rate (MMR), which is a critical health indicator that measures the number of maternal deaths per 100,000 live births in a specific population over a given period. It is used to assess the risk of death associated with pregnancy and childbirth, reflecting the overall health and access to healthcare services for pregnant women in a particular region or country.

72. MTP: Medical Termination of Pregnancy-

Medical Termination of Pregnancy (MTP), also known as abortion, is a medical procedure to terminate a pregnancy before the fetus reaches viability. Viability refers to the point at which the fetus is capable of surviving outside the womb, typically around 24 weeks of gestation. MTP is considered a safe and legal option in many countries to address unwanted pregnancies or pregnancies that pose a risk to the health of the pregnant woman.

73. MSH: Melanocyte Stimulating Hormone-

Melanocyte-stimulating hormone (MSH), is a peptide hormone produced by the pituitary gland in the brain. It plays a crucial role in the regulation of skin pigmentation, among other functions. There are several forms of MSH, with the most well-known being alpha-melanocyte-stimulating hormone (α-MSH).

74. MRI : Magnetic Resonance Imaging-

One of the medically used biology full forms is Magnetic Resonance Imaging (MRI), is a powerful medical imaging technique used to visualize internal structures of the body in high detail without using ionizing radiation. Instead, MRI relies on a combination of strong magnetic fields and radiofrequency waves to create detailed cross-sectional images of the body’s tissues and organs.

75. MOET :Multiple Ovulation Embryo Transfer Technology-

Multiple Ovulation Embryo Transfer (MOET) technology, also known as Superovulation and Embryo Transfer (SOET), is a reproductive biotechnology used in animal breeding to increase the number of offspring from genetically valuable female animals. MOET technology involves the controlled induction of superovulation in a female animal, followed by the collection of multiple eggs (ova) and their subsequent fertilization in vitro (outside the animal’s body). The resulting embryos are then transferred to surrogate or recipient animals for gestation and birth.

76. MALT : Mucosal Associated Lymphoid Tissue-

Mucosal-associated lymphoid tissue (MALT), is a specialized component of the immune system that is located in mucosal surfaces throughout the body. MALT is a part of the larger lymphoid tissue system and plays a crucial role in defending the body against pathogens that enter through mucous membranes, such as those in the respiratory, digestive, and urogenital tracts.

77. MMR: Measles, Mumps and Rubella-

Measles, mumps, and rubella (MMR), are three viral infections caused by different viruses that can affect humans, especially children. The MMR vaccine is a combination vaccine that provides immunity against all three diseases. It is widely used to prevent these viral infections and their associated complications.

78. MHD:  Magneto hydrodynamics-

Magneto hydrodynamics (MHD), is a branch of fluid dynamics that studies the behavior of electrically conducting fluids, such as plasmas, liquid metals, and ionized gases, in the presence of magnetic fields. It combines principles from magnetism and hydrodynamics to understand the interactions between magnetic fields and fluid flows.

79. NAD : Nicotinamide Adenine Dinucleotide (Coenzyme)-

One of the most used biology full forms is Nicotinamide Adenine Dinucleotide (NAD+), which is a coenzyme that plays a crucial role in various metabolic processes in all living cells. It is a derivative of vitamin B3 (niacin) and is involved in redox reactions, which are essential for energy production and numerous cellular processes.

80. NAA : Napthalene Acetic Acid-

Naphthalene acetic acid (NAA), is a synthetic plant growth regulator or plant hormone. It is a member of the auxin family, which are a class of plant hormones that play a vital role in regulating various aspects of plant growth and development. NAA is commonly used in agriculture, horticulture, and plant research to influence plant growth and development in desired ways.

81. NHC : Non-histone Chromosomal proteins-

Non-histone chromosomal proteins, which are a group of proteins that are associated with chromatin (the complex of DNA and proteins that make up chromosomes) but are not part of the histone protein family. Histones are the primary proteins responsible for packaging and organizing DNA into nucleosomes, which form the basic structural units of chromatin.

82. NPP: Net Primary Productivity-

Net Primary Productivity (NPP) is a critical ecological concept that measures the amount of energy that plants capture and store through photosynthesis, minus the energy they expend during cellular respiration. NPP represents the net gain of energy available to support the growth and reproduction of primary producers (plants) in an ecosystem. It is a fundamental measure of the rate at which plants convert solar energy into biomass.

83. OCD: Obsessive Compulsive Disorder-

One of the important biology full forms is Obsessive-Compulsive Disorder (OCD), is a mental health condition characterized by the presence of intrusive, distressing, and repetitive thoughts, images, or urges called obsessions, and the engagement in repetitive behaviors or mental acts, known as compulsions, in response to those obsessions. OCD is a chronic and potentially disabling condition that can significantly impact a person’s daily life and functioning.

84. OAA : Oxalo acetic acid-

Oxaloacetic acid (OAA), is a four-carbon organic acid and a crucial intermediate in several metabolic pathways in living organisms. It plays a central role in the citric acid cycle (also known as the Krebs cycle or TCA cycle) and is involved in gluconeogenesis, the process by which glucose is synthesized from non-carbohydrate precursors. Related to this biology full forms, you can read more about carbohydrates in this article: Structure and Function of 3 Most Important Carbohydrates.

85. Ori : Origin of Replication-

Origin of replication, is a specific DNA sequence within a chromosome or a plasmid where the process of DNA replication begins. It is the site where various proteins and enzymes bind to initiate the duplication of the DNA molecule. The origin of replication is essential for ensuring accurate and efficient DNA replication during cell division and other cellular processes.

86.OPD: Outpatient Department-

Outpatient Department (OPD), is a section or area in a hospital or medical facility where patients receive medical evaluation, diagnosis, treatment, and follow-up care without requiring an overnight stay. In contrast to inpatient care, where patients are admitted to the hospital for an extended period, the OPD provides medical services on an outpatient basis.

87. ppm : Parts per million-

Parts per million (ppm), is a unit of measurement used to express the concentration of a substance in a solution or mixture. It indicates the number of units of the substance present per one million units of the total solution or mixture. Parts per million is commonly used in various fields, including chemistry, environmental science, industry, and health.

88. PTH: Parathyroid hormone-

Parathyroid hormone (PTH), is a hormone produced and secreted by the parathyroid glands, which are four small glands located on the posterior surface of the thyroid gland in the neck. PTH plays a crucial role in the regulation of calcium and phosphorus levels in the body, helping to maintain a stable and appropriate concentration of these minerals in the bloodstream and tissues.

89. PGA: Phosphoglyceric acid-

Phosphoglyceric acid (PGA), also known as 3-phosphoglyceric acid (3-PGA), is a three-carbon organic compound that plays a central role in the process of photosynthesis, specifically during the Calvin cycle, which is the second phase of photosynthesis. PGA is an intermediate product formed during the carbon fixation stage of photosynthesis, where carbon dioxide is converted into organic compounds.

90. PPLO : Pleuro Pneumonia Like Organisms-

Pleuropneumonia-like organisms (PPLO), also known as Mycoplasma, are a group of bacteria that are distinct from typical bacteria due to their small size and lack of a cell wall. Mycoplasmas are among the smallest known free-living organisms and are considered to be the simplest bacteria in terms of cellular structure. They are capable of causing various diseases in humans, animals, and plants.

91.PGRS: Plant Growth Regulators-

Plant Growth Regulators (PGRs), also known as plant hormones or phytohormones, are naturally occurring organic compounds that play a crucial role in regulating various physiological processes in plants. These hormones control growth, development, and responses to environmental stimuli. PGRs act at low concentrations and are produced in one part of the plant and transported to other parts to exert their effects.

92. PMC : Pollen mother cell-

A pollen mother cell (PMC), also known as a microsporocyte, is a specialized cell found in the anther of a flower, which is the male reproductive organ of flowering plants. The primary function of the PMC is to undergo meiosis, a type of cell division, to produce haploid microspores. These microspores eventually develop into pollen grains, which are the male gametophytes responsible for fertilizing the female reproductive organs (ovules) of the flower.

93. PEN : Primary Endosperm Nucleus-

Primary Endosperm Nucleus (PEN), is a specialized nucleus that forms in the embryo sac of angiosperms during double fertilization, a unique reproductive process in flowering plants. Double fertilization involves the fusion of two sperm cells with two different female gametophytic cells to give rise to both the embryo and the endosperm, which is a nutrient-rich tissue that supports the developing embryo.

94. PCR: Polymerase Chain Reaction-

One of the most used biology full forms in the field of biotechnology is Polymerase Chain Reaction (PCR), is a powerful molecular biology technique used to amplify a specific segment of DNA in a test tube. PCR allows researchers to produce multiple copies of a particular DNA fragment from a small initial sample, enabling the study and analysis of DNA sequences in various applications, including research, diagnostics, forensic analysis, and biotechnology.

95. ppb: Parts per billion-

Parts per billion (ppb), is a unit of measurement used to express very small concentrations of a substance in a mixture. It indicates the number of units of the substance present per one billion (1,000,000,000) units of the total mixture. Parts per billion is commonly used in various scientific fields, especially in environmental science, chemistry, and toxicology, where extremely low concentrations of substances are of interest.

96. RuBisCO : Ribulose bisphosphate carboxylase-oxygenase-

Ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO), is an essential enzyme found in all photosynthetic organisms, including plants, algae, and cyanobacteria. It plays a central role in the process of carbon fixation during photosynthesis, specifically in the Calvin cycle.

97. RQ: Respiratory Quotient-

in physiology one of the most used biology full forms is the Respiratory Quotient (RQ), also known as the Respiratory Exchange Ratio (RER), is a physiological measurement that relates the amount of carbon dioxide (CO2) produced to the amount of oxygen (O2) consumed during cellular respiration. It is used to evaluate the type of fuel being metabolized by an organism or cell for energy production. The respiratory quotient provides valuable information about the metabolic processes occurring in the body and can vary depending on the type of nutrients being utilized.

98. RTI: Reproductive Tract Infection-

Reproductive Tract Infection (RTI) refers to any infection that affects the reproductive organs in both males and females. These infections can involve various parts of the reproductive system, including the genitals, the uterus, fallopian tubes, ovaries in females, and the testes and epididymis in males. RTIs can be caused by bacteria, viruses, fungi, or parasites and can lead to various symptoms and complications if left untreated.

99.RBC: Red Blood Cell-

in hematology one of the most used biology full forms is Red Blood Cells (RBCs), also known as erythrocytes, are the most abundant type of blood cells in the human body. They play a critical role in oxygen transport from the lungs to body tissues and carbon dioxide transport from tissues back to the lungs for elimination.

100. RTA: Renal Tubular Acidosis-

Renal Tubular Acidosis (RTA), is a medical condition characterized by the inability of the kidneys to properly regulate acid-base balance in the body. Normally, the kidneys are responsible for filtering waste products, including acids, from the blood and excreting them in the urine. In RTA, there is a defect in the kidney’s ability to reabsorb bicarbonate (a base) or excrete hydrogen ions (acids), leading to an accumulation of acid in the blood, resulting in acidosis.

101. RNA: Ribonucleic Acid-

Ribonucleic Acid, commonly known as RNA, is a molecule essential for various biological processes in living organisms. It is a linear polymer made up of nucleotides, just like its counterpart, Deoxyribonucleic Acid (DNA). RNA plays a central role in gene expression and protein synthesis within cells. You can read more about this biology full forms in this article: DNA and RNA Structure and Function | Structure and Function of Nucleic Acids.

102. RO: Reverse Osmosis-

Reverse osmosis (RO), is a water purification process that uses a semi-permeable membrane to remove dissolved salts, impurities, and contaminants from water. It is a type of filtration method that allows water molecules to pass through the membrane while blocking the passage of larger particles and dissolved substances. The process is called “reverse” osmosis because it operates opposite to the natural osmosis process.

103. snRNA: Small Nuclear RNA-

Small Nuclear RNA (snRNA), is a class of short RNA molecules found in the cell nucleus of eukaryotic organisms. These RNAs play crucial roles in the processing of pre-messenger RNA (pre-mRNA) and its conversion into mature mRNA. snRNAs are essential components of the spliceosome, a large ribonucleoprotein complex responsible for RNA splicing. You can read more about this biology full forms in this article: The Structure and Function of Small Nuclear RNA (snRNA).

104. sRNA: Soluble RNA-

Soluble RNA (sRNA), is an outdated term that was previously used to refer to Transfer RNA (tRNA). Transfer RNA is a type of RNA molecule involved in protein synthesis (translation) within cells. It carries specific amino acids to the ribosomes during the translation process, where they are assembled into a polypeptide chain according to the information encoded in the messenger RNA (mRNA). If you want to read another such biology full forms, then go through this article: Structure and Function of Small Nucleolar RNA (snoRNA).

105. STDS: Sexually Transmitted Diseases-

Sexually Transmitted Diseases (STDs), also known as Sexually Transmitted Infections (STIs), which are infections that are primarily transmitted through sexual contact. They can be caused by bacteria, viruses, parasites, and other microorganisms.

106. SCP: Single Cell Protein-

Single Cell Protein (SCP) refers to a type of protein-rich biomass derived from the growth of single-celled microorganisms, such as bacteria, yeasts, fungi, and algae. These microorganisms are cultivated in large-scale bioreactors or fermentation tanks and can be a valuable source of protein for human and animal consumption.

107.STPs: Sewage Treatment Plants-

In ecology one of the most used biology full forms is Sewage Treatment Plants (STPs), are facilities designed to treat and process wastewater (sewage) to remove contaminants and pollutants before discharging the treated water back into the environment or reusing it for various purposes. Sewage treatment is essential for protecting public health, safeguarding water quality, and preserving the natural environment.

108. SGOT: Serum Glutamic Oxaloacetic Transaminase-

Serum Glutamic Oxaloacetic Transaminase, commonly known as SGOT or AST (Aspartate Aminotransferase), which is an enzyme found primarily in the cells of the liver, heart, muscles, and other tissues. It plays a crucial role in the metabolism of amino acids and is involved in transferring an amino group from aspartate to alpha-ketoglutarate, generating oxaloacetate and glutamate in the process.

109. SGPT: Serum Glutamic Pyruvic Transaminase-

Serum Glutamic Pyruvic Transaminase, also known as SGPT or ALT (Alanine Aminotransferase), is an enzyme found primarily in the cells of the liver, as well as in smaller amounts in the heart, kidneys, and skeletal muscles. Like SGOT/AST (Aspartate Aminotransferase), ALT plays a critical role in amino acid metabolism, specifically in transferring an amino group from alanine to alpha-ketoglutarate, generating pyruvate and glutamate in the process.

110. TT: Tetanus Toxoid-

Tetanus toxoid is a vaccine used to prevent tetanus, a severe and potentially life-threatening bacterial infection caused by the bacterium Clostridium tetani. The tetanus bacteria produce a potent neurotoxin known as tetanospasmin, which affects the nervous system and leads to muscle stiffness and spasms.

111. Ti Plasmid : Tumor Inducing Plasmid-

A Tumor-Inducing Plasmid, also known as a Ti plasmid (Tumor-inducing plasmid), is a type of plasmid found in some strains of plant-pathogenic bacteria, particularly in Agrobacterium tumefaciens and Agrobacterium rhizogenes. These plasmids play a significant role in the development of plant tumors, also known as crown galls or hairy roots.

112. Taq : Thermus aquaticus-

Thermus aquaticus is a thermophilic bacterium that thrives in hot springs and other high-temperature environments. It is particularly well-known for its heat-resistant enzyme called Taq DNA polymerase, which is widely used in the polymerase chain reaction (PCR) technique.

113. TSH : Thyroid Stimulating Hormone-

Thyroid-Stimulating Hormone (TSH), also known as thyrotropin, is a hormone produced and released by the pituitary gland, a small gland located at the base of the brain. TSH plays a crucial role in regulating the function of the thyroid gland, which is an essential organ in the endocrine system responsible for producing thyroid hormones.

114. T3 : Triodothyronine-

In endocrinology one of the most used biology full forms is Triiodothyronine (T3) is one of the two main thyroid hormones produced by the thyroid gland, with the other being thyroxine (T4). T3 is the biologically active form of thyroid hormone, and it plays a vital role in regulating metabolism and various physiological processes in the body.

115. T4: Tetraiodothyronine or thyroxine-

Tetraiodothyronine, more commonly known as thyroxine or T4, is one of the two main thyroid hormones produced by the thyroid gland. The other thyroid hormone is triiodothyronine (T3). Thyroxine is a prohormone, meaning it is an inactive precursor of the biologically active hormone T3.

116. TCT: Thyrocalcitonin-

Thyrocalcitonin, also known as calcitonin, is a hormone produced by special cells, known as C-cells or parafollicular cells, located in the thyroid gland. Unlike thyroxine (T4) and triiodothyronine (T3), which are produced by the follicular cells of the thyroid, calcitonin is synthesized by a different population of cells within the same gland.

117. VNTR: Variable Number of Tandem Repeats-

Variable Number of Tandem Repeats (VNTRs), is a type of DNA sequence variation characterized by the presence of short, repeating DNA sequences arranged in tandem repeats at a specific chromosomal locus. In VNTRs, the number of repeats can vary significantly between individuals, leading to allelic diversity.

118. WBC: White Blood Cell-

White blood cells (WBCs), also known as leukocytes, are a crucial component of the body’s immune system. They play a vital role in protecting the body against infections and diseases. WBCs are produced and primarily found in the bone marrow, but they can also circulate throughout the bloodstream and various tissues.

119. WHO World Health Organization-

One of the most used biology full forms is World Health Organization (WHO), a specialized agency of the United Nations (UN) responsible for coordinating and promoting international public health efforts. It was established on April 7, 1948, and its headquarters are located in Geneva, Switzerland. The WHO is the leading international authority on global health issues and works closely with governments, organizations, and communities worldwide to improve public health and ensure equitable access to healthcare for all.

120. YAC : Yeast Artificial Chromosome-

in biotechnology one of the most used biology full forms is Yeast Artificial Chromosome (YAC) is a type of artificial chromosome used in genetic engineering and molecular biology to clone and study large fragments of DNA. YACs are derived from the yeast Saccharomyces cerevisiae, which is a commonly used model organism in genetic research.

121. ZIFT: Zygote Intra-fallopian transfer-

Zygote Intra-Fallopian Transfer (ZIFT), is an assisted reproductive technology (ART) procedure used to treat infertility in couples who have difficulty conceiving naturally. It is a variation of in vitro fertilization (IVF) and involves the fertilization of an egg (zygote) in the laboratory and then transferring the fertilized egg into the fallopian tube. 

These biology full forms are not only used in the study of biology, rather these can be the answers to many short questions in competitive examinations. These biology full forms are also used in higher studies, such as PS means Photoluminescence Spectroscopy which is useful in determining the electronic structure and properties of materials. 

Lipids structure are a diverse group of biomolecules that play critical roles in various biological processes. Composed primarily of carbon, hydrogen, and oxygen. Lipids exhibit a remarkable structural and functional diversity that underlies their importance in cellular membranes, energy storage, and signaling pathways. In this article, we will delve into the composition, structure, and functions of lipids, shedding light on their essential roles in maintaining cellular homeostasis and supporting life processes.

To know the other biomolecules read the article: 5 Major Biomolecules in Life | Chemical Constituents of Life.

Composition of Lipids Structure:

In Lipids structure lipids are hydrophobic molecules, which means they are insoluble in water but soluble in organic solvents like chloroform, ether, and benzene. The core building block of lipids structure is the fatty acid, a long hydrocarbon chain with a carboxyl group at one end. Fatty acids vary in length, ranging from a few to several carbon atoms. They can be saturated, where each carbon atom forms single bonds with adjacent carbon atoms, or unsaturated, containing one or more double bonds between carbon atoms.

Lipids structure are organic compounds primarily composed of carbon, hydrogen, and oxygen atoms. However, unlike carbohydrates, lipids have a lower proportion of oxygen atoms relative to carbon and hydrogen. This characteristic gives lipids their hydrophobic nature, making them insoluble in water. The main building blocks of lipids are fatty acids, which consist of a long hydrocarbon chain with a carboxyl group (-COOH) at one end. The variations in fatty acid chain length, saturation, and functional groups lead to the diversity observed in lipid structures.

If you want to about the full forms of biology then read the article: The 121 Biology Full Forms Alphabetically Arranged.

Properties of Lipids Structure:

Property	Description
Hydrophobicity	Lipids structure are hydrophobic (water-fearing) molecules due to their nonpolar nature. They are insoluble in water but soluble in nonpolar solvents such as chloroform or ether.
Insulation and Protection	Lipids, particularly adipose tissue, act as insulation by providing a layer of fat beneath the skin, which helps in maintaining body temperature and protecting vital organs.
Energy Storage	Lipids serve as an efficient energy storage form in the body. They contain more energy per unit weight compared to carbohydrates and can be stored in adipose tissue as triglycerides.
Structural Diversity	Lipids exhibit structural diversity with various classes such as fatty acids, glycerolipids, phospholipids, sphingolipids, and sterols, each having unique structures and functions.
Cell Membrane Component	Lipids are a crucial component of cell membranes. Phospholipids and cholesterol contribute to the fluidity, stability, and selective permeability of cell membranes.
Signaling Molecules	Certain lipids act as signaling molecules, participating in cell signaling and communication pathways. Examples include lipid mediators such as prostaglandins and leukotrienes.

Lipids Structure:

Lipids exhibit an extensive array of structures due to the different arrangements and modifications of their constituent fatty acids. Major classes of lipids include triglycerides, phospholipids, steroids, and waxes. Triglycerides, commonly found in adipose tissue, serve as the primary energy storage molecules in organisms. They consist of three fatty acid chains esterified to a glycerol backbone. The nature of the fatty acids determines whether a triglyceride is classified as saturated or unsaturated.

Phospholipids, another critical class of lipids, form the building blocks of cell membranes. They contain two fatty acid chains and a phosphate group attached to a glycerol molecule. The hydrophilic phosphate head and hydrophobic fatty acid tails enable phospholipids to arrange in a bilayer, forming the lipid bilayer structure of cell membranes.

Steroids, such as cholesterol, are lipids with a distinct structure consisting of four fused carbon rings. Cholesterol plays a crucial role in cell membrane fluidity and serves as a precursor for the synthesis of important molecules, including hormones. Waxes are highly saturated lipids that provide waterproofing and protective functions, commonly found in the cuticles of plants and the outer layer of animal fur.

Examples of Different Types of Lipids Structure:

Lipid Type	Examples
Fatty Acids	Palmitic acid, Oleic acid, Linoleic acid
Glycerolipids	Triglycerides, Diglycerides, Monoglycerides
Phospholipids	Phosphatidylcholine, Phosphatidylethanolamine, Sphingomyelin
Sphingolipids	Ceramides, Sphingosine, Glycosphingolipids
Sterols	Cholesterol, Ergosterol, Sitosterol
Waxes	Beeswax, Carnauba wax, Lanolin

Classification of Lipids Based on The Lipids Structure:

Simple Lipids Structure:

Simple lipids, also known as neutral lipids, are esters of fatty acids with various alcohols. The most common examples are triglycerides, which consist of three fatty acid chains esterified to a glycerol molecule. Triglycerides serve as the primary storage form of energy in adipose tissue and are an efficient means of long-term energy storage.

Complex Lipids Structure:

Complex lipids are esters of fatty acids that contain additional components beyond glycerol. Phospholipids are a crucial class of complex lipids, characterized by the presence of a phosphate group. Phospholipids are the major constituents of cellular membranes, forming a phospholipid bilayer that provides structural integrity and regulates the flow of molecules into and out of cells. Another important group of complex lipids is sphingolipids, which have a sphingosine or a similar backbone. Sphingomyelin, a type of sphingolipid, is a key component of myelin, the protective sheath surrounding nerve fibers. Sphingolipids also participate in cell signaling pathways and act as determinants of cellular recognition and adhesion.

Derived Lipids Structure:

Derived lipids are derived from simple or complex lipids through enzymatic or chemical processes. Examples of derived lipids include sterols, such as cholesterol, which are crucial for maintaining cell membrane fluidity and serving as precursors for hormones like estrogen and testosterone. Eicosanoids, another class of derived lipids, are involved in inflammatory responses, blood clotting, and regulation of blood pressure.

Classification of Lipids Structure Based on Fatty Acid Chains:

One of the key characteristics of lipids is their structural diversity, which stems from variations in their fatty acid chains. This article provides a comprehensive overview of the classification of lipids based on the types of fatty acid chains they possess.

1. Saturated Fatty Acids:

Saturated fatty acids consist of carbon chains that lack double bonds between the carbon atoms. These fatty acids are typically solid at room temperature and are found abundantly in animal fats, such as butter and lard. Saturated fats have been associated with an increased risk of cardiovascular diseases and are often considered less healthy compared to other types of lipids.

2. Unsaturated Fatty Acids:

Unsaturated fatty acids contain one or more double bonds between carbon atoms in their carbon chains. They can be further classified into two main categories:

a. Monounsaturated Fatty Acids (MUFA): Monounsaturated fatty acids possess a single double bond in their carbon chains. These fatty acids are commonly found in plant-based oils, including olive oil and avocado oil. MUFA-rich diets have been associated with various health benefits, such as improved heart health and reduced inflammation.

b. Polyunsaturated Fatty Acids (PUFA): Polyunsaturated fatty acids contain two or more double bonds in their carbon chains. Omega-3 and omega-6 fatty acids are examples of PUFA. These essential fatty acids cannot be synthesized by the human body and must be obtained through dietary sources. Omega-3 fatty acids are found in fatty fish, flaxseeds, and walnuts, while omega-6 fatty acids are abundant in vegetable oils. Both omega-3 and omega-6 fatty acids play crucial roles in maintaining proper cellular function, supporting brain health, and reducing the risk of chronic diseases.

3. Trans Fatty Acids:

Trans fatty acids are unsaturated fatty acids with a specific arrangement of hydrogen atoms around their double bonds. They can be either naturally occurring or artificially produced through hydrogenation processes. Artificial trans fats are commonly found in processed foods, baked goods, and fried items. Unlike other unsaturated fats, trans fats have been strongly associated with increased cardiovascular risks and should be minimized in dietary intake.

Examples of different types of fatty acids:

Type of Fatty Acid	Carbon Chain Length	Examples
Short-chain Fatty Acids	Fewer than six carbon atoms	Acetic acid (C2:0), Propionic acid (C3:0), Butyric acid (C4:0)
Medium-chain Fatty Acids	Six to twelve carbon atoms	Caproic acid (C6:0), Caprylic acid (C8:0), Lauric acid (C12:0)
Long-chain Fatty Acids	More than twelve carbon atoms	Palmitic acid (C16:0), Stearic acid (C18:0), Oleic acid (C18:1)
Omega-3 Fatty Acids	Varies	Alpha-linolenic acid (ALA), Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA)
Omega-6 Fatty Acids	Varies	Linoleic acid (LA), Arachidonic acid (AA)

If you want to see the NEET syllabus then go to the article: NEET Biology Syllabus 2024 Chapter Wise | Biology NEET Syllabus.

Examples of different types of fatty acids with their sources:

Type of Fatty Acid	Examples	Food Sources
Short-chain Fatty Acids	Acetic acid (C2:0)	Vinegar, fermented foods, and dairy products
Short-chain Fatty Acids	Propionic acid (C3:0)	Swiss cheese, fermented foods
Short-chain Fatty Acids	Butyric acid (C4:0)	Butter, ghee, fermented foods
Medium-chain Fatty Acids	Caproic acid (C6:0)	Coconut oil, palm kernel oil
Medium-chain Fatty Acids	Caprylic acid (C8:0)	Coconut oil, palm kernel oil
Medium-chain Fatty Acids	Lauric acid (C12:0)	Coconut oil, palm kernel oil, breast milk
Long-chain Fatty Acids	Palmitic acid (C16:0)	Meat, dairy products, palm oil, olive oil
Long-chain Fatty Acids	Stearic acid (C18:0)	Meat, cocoa butter, shea butter
Long-chain Fatty Acids	Oleic acid (C18:1)	Olive oil, avocados, nuts, seeds
Omega-3 Fatty Acids	Alpha-linolenic acid (ALA)	Flaxseeds, chia seeds, walnuts, hemp seeds
Omega-3 Fatty Acids	Eicosapentaenoic acid (EPA)	Fatty fish (salmon, mackerel, sardines)
Omega-3 Fatty Acids	Docosahexaenoic acid (DHA)	Fatty fish (salmon, mackerel, sardines)
Omega-6 Fatty Acids	Linoleic acid (LA)	Vegetable oils (soybean, sunflower, safflower), nuts, seeds
Omega-6 Fatty Acids	Arachidonic acid (AA)	Meat, eggs, poultry, organ meats

Classification of Lipids Structure Based on the Saponification Property:

They can be classified into two major categories: saponifiable lipids and non-saponifiable lipids:

Saponifiable Lipids structure:

Saponifiable lipids structure are those that can be hydrolyzed by alkali (such as sodium hydroxide) to yield their respective components. The major class of saponifiable lipids is known as glycerolipids, which are esters of fatty acids with glycerol. Glycerolipids include triglycerides, diglycerides, and monoglycerides.

• Triglycerides: Triglycerides are the most abundant form of dietary fats and serve as the primary storage form of energy in organisms. They consist of three fatty acids esterified to a glycerol backbone. Triglycerides are found in adipose tissue and serve as an energy reserve, insulation, and protection for organs.
• Diglycerides and Monoglycerides: Diglycerides and monoglycerides are intermediate products formed during the digestion and metabolism of triglycerides. They play roles in the absorption and transport of dietary lipids, as well as being utilized in various cellular processes.

Non-Saponifiable Lipids structure:

Non-saponifiable lipids structure, as the name suggests, are lipids that cannot be hydrolyzed by alkali. They include several important classes of lipids, each with distinct functions and structures.

• Sterols: Sterols are a class of non-saponifiable lipids that have a specific structure containing a sterane nucleus. Cholesterol is the most well-known sterol and plays a vital role in maintaining cell membrane integrity, serving as a precursor for hormones, and aiding in the production of bile acids.
• Terpenes: Terpenes are hydrocarbons derived from the polymerization of isoprene units. They have diverse functions in organisms, serving as pigments (such as carotenoids), components of essential oils, and playing roles in the synthesis of hormones, such as steroid hormones.
• Prostaglandins: Prostaglandins are lipid molecules derived from arachidonic acid, a polyunsaturated fatty acid. They act as local hormones and play significant roles in various physiological processes, including inflammation, blood clotting, and smooth muscle contraction.
• Fat-Soluble Vitamins: Vitamins A, D, E, and K are classified as fat-soluble vitamins and are non-saponifiable lipids. These vitamins are essential for various biological functions, including vision, bone health, antioxidant protection, and blood clotting.

Read the another aspect of lipids in the article: What are lipids?

Some Well Known Lipids Structure:

Lipid Type	Composition	Structure	Function	Examples	Sources
Waxes	Esters of long-chain fatty acids and alcohols	Long hydrocarbon chains with ester linkages	Water-repellent properties, protection, lubrication	Beeswax, Carnauba wax, Lanolin	Plants (e.g., leaves, fruits), animals (e.g., bees)
Steroids	Four fused carbon rings	Sterane nucleus with various functional groups	Hormones, cell membrane structure, regulation of physiological processes	Cholesterol, Estrogen, Testosterone	Animal tissues, plants (phytosterols), synthesized in the body
Cholesterols	Steroids with a hydroxyl group	Sterane nucleus with a hydroxyl group	Cell membrane structure, hormone synthesis, bile acid production	Cholesterol, Phytosterols, Ergosterol	Animal tissues, plants, synthesized in the body
Phospholipids	Glycerol, two fatty acids, and a phosphate group	Phosphate group, polar head with fatty acid tails	Major components of cell membranes, cell signaling	Phosphatidylcholine, Phosphatidylethanolamine	Plant and animal cell membranes

Functions of Lipids Structure:

1. Energy Storage: Triglycerides store energy in adipose tissue, serving as a concentrated source of metabolic fuel. When energy demand increases, triglycerides are hydrolyzed into fatty acids, which can be oxidized to produce ATP, the cell’s primary energy currency.
2. Structural Role: Among lipids structure, particularly phospholipids, form the structural basis of cellular membranes. The phospholipid bilayer provides a selectively permeable barrier that separates the cell from its environment, facilitating cellular processes and maintaining internal homeostasis.
3. Signaling and Communication: Lipids structure act as signaling molecules and play crucial roles in cellular communication. Phospholipids and sphingolipids participate in signal transduction pathways, modulating cellular responses to external stimuli. Eicosanoids and other lipid mediators regulate inflammation, blood clotting, and immune responses.

If you want to know about the differences between the snRNA and snoRNA then read the article: Differences Between snRNAs and snoRNAs

Because of the diverse lipids structure lipids are diverse and essential biomolecules that contribute to numerous biological processes. From energy storage to structural support and cellular signaling, lipids play pivotal roles in maintaining cellular homeostasis and supporting life’s fundamental processes. Understanding of the lipids structure, composition, and functions are not only provides insights into cellular biology but also offers potential avenues for developing therapies and interventions targeting lipid-related diseases.

Small Nucleolar RNA (snoRNA) represent a fascinating class of non-coding RNAs that play crucial roles in the intricate machinery of cellular processes. Found predominantly within the nucleus of eukaryotic cells, snoRNAs are characterized by their small size and pivotal involvement in the modification and processing of other RNA molecules.

Full Form of snoRNA:

SnoRNA stands for Small Nucleolar RNA. This nomenclature not only underscores the petite size of these RNA molecules but also highlights their predominant localization within the nucleolus, a subnuclear compartment essential for the processing of ribosomal RNA (rRNA). The full form succinctly captures the essence of Small Nucleolar RNA (snoRNA) as pivotal players in the intricate symphony of genetic regulation.

Size and Length of Small Nucleolar RNA (snoRNA):

The size and length of these molecules, though modest in comparison to other RNA species, carry profound functional implications.

SnoRNA Size and Length:

• SnoRNAs exhibit a compact size, typically ranging from 60 to 300 nucleotides. This modest length, relative to other RNA molecules, is a defining characteristic of snoRNAs.
• The size of snoRNAs reflects their role as guide molecules, facilitating specific interactions with target RNAs during the modification process.

Genomic Origins Influence Size:

• The size of snoRNAs is influenced by their genomic origins. SnoRNAs can be located within the introns of host genes, which may be protein-coding or non-coding.
• The length of the host gene, along with the specific snoRNA sequence within the host, contributes to the final size of the Small Nucleolar RNA (snoRNA) product.

Functional Implications of Size:

• The size of snoRNAs is intricately linked to their functional roles in guiding specific modifications. The compact structure allows for precise base-pairing interactions with target RNAs, facilitating the recruitment of modifying enzymes to specific sites.
• Size variations among snoRNAs may reflect functional adaptations to their roles in guiding modifications on various RNA species, including ribosomal RNA, transfer RNA, and small nuclear RNA.

If you want to know about the snRNA then read the article: The Structure and Function of Small Nuclear RNA (snRNA)

Structural Characteristics of Small Nucleolar RNA (snoRNA):

Small Nucleolar RNA (snoRNA) is small yet powerful RNA molecules boast a unique architecture that belies their significant roles in orchestrating modifications crucial for the maturation of various RNA species.

Conserved Motifs: Small Nucleolar RNA (snoRNA) exhibit characteristic conserved motifs that define their identity and functionality. These motifs often include short, conserved sequences crucial for the recognition and interaction with target RNA molecules. The conserved nature of these motifs underscores the evolutionary importance of snoRNAs in maintaining cellular homeostasis.

Two Main Classes: SnoRNAs are broadly classified into two main classes based on their structural characteristics and the type of modifications they guide. The two classes are box C/D snoRNAs and box H/ACA snoRNAs. Each class has a distinctive secondary structure that enables them to recognize specific target RNAs and facilitate the precise chemical modifications required for their maturation.

Box C/D snoRNAs: These snoRNAs feature conserved boxes C (UGAUGA) and D (CUGA), forming a characteristic stem-loop structure. The C and D boxes are essential for the assembly of protein complexes responsible for 2′-O-methylation of the target RNA.

Box H/ACA snoRNAs: These snoRNAs possess a hairpin-hinge-hairpin-tail structure, with conserved H (ANANNA) and ACA boxes. The H/ACA snoRNAs guide the pseudouridylation of target RNA molecules, facilitating the formation of isomeric uridine.

RNA-Protein Interactions: The functionality of snoRNAs relies heavily on their ability to form dynamic RNA-protein complexes. These complexes, known as small nucleolar ribonucleoproteins (snoRNPs), involve interactions between snoRNAs and specific proteins. These proteins not only stabilize the snoRNA structure but also actively contribute to the guidance of modifications on target RNAs.

Localization in the Nucleolus: SnoRNAs are predominantly localized within the nucleolus, a specialized subnuclear compartment. This specific localization is crucial for their role in ribosomal RNA processing and modification, highlighting the intimate connection between snoRNA structure and function within the cellular context.

If you want to know about the differences between the snRNA and snoRNA then read the article: Differences Between snRNAs and snoRNAs

Functions of Small Nucleolar RNA (snoRNA):

Despite their modest size, Small Nucleolar RNA (snoRNA) play multifaceted roles that extend far beyond their unassuming appearance.

Guiding RNA Modifications:

The primary function of Small Nucleolar RNA (snoRNA) revolves around their role as precision guides for the modification of other RNA molecules. Two main classes of snoRNAs, box C/D and box H/ACA, each specialize in guiding distinct modifications – 2′-O-methylation and pseudouridylation, respectively. Through intricate base-pairing interactions with target RNAs, snoRNAs direct specific protein complexes to precise sites, orchestrating modifications that influence the structural and functional properties of the target RNAs.

Ribosomal RNA (rRNA) Maturation:

One of the pivotal functions of snoRNAs is their involvement in ribosome biogenesis. Within the nucleolus, snoRNAs play a crucial role in modifying and processing rRNA, the building blocks of ribosomes. By guiding modifications such as 2′-O-methylation and pseudouridylation, snoRNAs contribute to the maturation of functional ribosomal subunits. This intricate process ensures the production of fully functional ribosomes, essential for cellular protein synthesis.

Maintenance of RNA Integrity:

SnoRNAs extend their influence beyond the nucleolus, participating in the maintenance of RNA integrity across various cellular processes. Studies have revealed their involvement in the splicing of pre-mRNA, highlighting their versatility in influencing the broader landscape of genetic regulation. This expanded functionality underscores the significance of snoRNAs in preserving the fidelity of the cellular transcriptome.

Dynamic RNA-Protein Interactions:

The functions of snoRNAs are intricately tied to their ability to form dynamic RNA-protein complexes known as small nucleolar ribonucleoproteins (snoRNPs). These complexes not only stabilize the structure of snoRNAs but also actively contribute to their functionality. The collaboration between snoRNAs and specific proteins ensures the precision and accuracy of the guided modifications on target RNAs.

Implications for Human Health:

As our understanding of snoRNA functions deepens, the implications for human health become increasingly apparent. Dysregulation of snoRNA expression or function has been linked to various diseases, including cancer and neurological disorders. The pivotal roles played by snoRNAs in fundamental cellular processes underscore their potential as therapeutic targets for interventions aimed at restoring cellular homeostasis.

Small Nucleolar RNA (snoRNA) Genes:

Deep within the genetic code lies a class of genes that encode the architects of cellular precision—Small Nucleolar RNA (snoRNA) genes.

Genomic Landscape of snoRNA Genes:

Small Nucleolar RNA (snoRNA) genes are scattered throughout the genome, residing in both protein-coding and non-coding regions. They can be found in intergenic regions, introns of protein-coding genes, or even within the introns of other non-coding RNAs. The dispersed distribution of snoRNA genes underscores their diverse origins and highlights the complex genomic landscape that governs their expression.

Promoter Elements and Transcription:

The transcriptional regulation of Small Nucleolar RNA (snoRNA) genes is orchestrated by specific promoter elements that initiate the synthesis of precursor snoRNAs. These precursor molecules, known as primary transcripts or host genes, undergo further processing to yield mature snoRNAs. The transcriptional regulation of snoRNA genes is finely tuned, ensuring that the cellular orchestra has access to these critical regulators of RNA modification.

Classes of snoRNA Genes:

SnoRNA genes can be broadly classified into two main categories based on the type of modifications they guide—box C/D snoRNA genes and box H/ACA snoRNA genes.

1. Box C/D snoRNA Genes:
   • Prominent for their conserved motifs, box C/D snoRNA genes typically contain characteristic boxes C (UGAUGA) and D (CUGA) within their sequences.
   • These genes guide 2′-O-methylation modifications on target RNAs through the formation of small nucleolar ribonucleoproteins (snoRNPs).
2. Box H/ACA snoRNA Genes:
   • Distinguished by their hairpin-hinge-hairpin-tail structure, box H/ACA snoRNA genes carry conserved H (ANANNA) and ACA boxes.
   • These genes guide the pseudouridylation of target RNAs, a modification crucial for RNA stability and function.

Evolutionary Conservation:

The genomic sequences encoding snoRNA genes often exhibit a degree of evolutionary conservation, underscoring their functional significance across diverse species. This conservation highlights the crucial roles played by snoRNAs in maintaining cellular homeostasis and suggests that these genes have been preserved throughout evolution due to their indispensable functions.

Functional Implications:

Understanding snoRNA genes provides insights into the regulation of RNA modifications and the broader landscape of genetic regulation. Dysregulation or mutations in snoRNA genes have been associated with various diseases, emphasizing their role in maintaining cellular health. Investigating the functional implications of snoRNA genes opens avenues for exploring their therapeutic potential in diseases where RNA modification plays a critical role.

Sequencing Techniques for Small Nucleolar RNA (snoRNA):

The advent of advanced sequencing technologies has opened new avenues for exploring the diversity and dynamics of snoRNAs, shedding light on their intricate functions within the cellular landscape.

1. RNA-Seq:
   • High-throughput RNA sequencing, known as RNA-Seq, has revolutionized the field of genomics by enabling the comprehensive profiling of the transcriptome.
   • RNA-Seq techniques are employed to capture and sequence the entire pool of cellular RNAs, providing a global view of snoRNA expression levels and their relative abundance.
2. Small RNA-Seq:
   • Given the small size of snoRNAs, specialized sequencing techniques known as small RNA-Seq have been developed to specifically capture and sequence short RNA molecules.
   • Small RNA-Seq enables the identification and quantification of snoRNAs within a sample, offering insights into their abundance and diversity.
3. Northern Blotting:
   • While traditional, Northern blotting remains a valuable technique for confirming the presence of specific snoRNAs and assessing their expression levels.
   • Northern blotting allows for the visualization of snoRNAs based on size, confirming their identity and providing information about their transcript size.
4. Rapid Amplification of cDNA Ends (RACE):
   • RACE techniques are utilized to obtain the full-length sequence of snoRNAs, facilitating a detailed understanding of their structural characteristics and potential isoforms.
   • RACE sequencing enhances our ability to precisely annotate snoRNA sequences and identify variations in their length or structure.

Functional Insights from Small Nucleolar RNA (snoRNA) Sequencing:

Identification of Novel Small Nucleolar RNA (snoRNA):

High-throughput sequencing has enabled the discovery of novel snoRNAs, expanding our catalog of these regulatory molecules.

Computational analyses of sequencing data contribute to the identification and annotation of previously unknown snoRNA sequences.

Expression Profiling:

Sequencing data provides valuable information about the expression levels of snoRNAs across different tissues, developmental stages, or under varying cellular conditions.

Comparative analysis of expression profiles offers insights into the regulatory networks in which snoRNAs participate.

Isoform Diversity:

Detailed sequencing allows for the identification of snoRNA isoforms, shedding light on the potential functional diversity within this class of non-coding RNAs.

Understanding snoRNA isoforms contributes to a more nuanced comprehension of their roles in guiding RNA modifications.

Processing of Small Nucleolar RNA (snoRNA):

Within the intricate machinery of cellular processes, the journey of Small Nucleolar RNA (snoRNA) from their genomic origin to functional maturity involves a series of precise and intricate processing steps.

Genomic Origins of snoRNAs:

SnoRNAs are encoded in the genome within specific genes or as part of larger RNA molecules. The majority of snoRNAs are intragenic, residing within the introns of protein-coding genes or even within other non-coding RNAs. Understanding their genomic origins is crucial for appreciating the diversity of snoRNA processing mechanisms.

Transcription and Primary Transcript:

The journey of Small Nucleolar RNA (snoRNA) begins with transcription. The host genes, often protein-coding or other non-coding RNA genes, are transcribed by RNA polymerase II. This initial transcript, known as the primary transcript, serves as the precursor for snoRNAs and undergoes further processing steps to give rise to mature snoRNAs.

Box C/D and Box H/ACA snoRNAs:

Two major classes of snoRNAs, box C/D and box H/ACA, undergo distinct processing pathways.

1. Box C/D snoRNAs:
   • The primary transcript of box C/D snoRNAs typically contains conserved motifs known as boxes C (UGAUGA) and D (CUGA).
   • These motifs guide the recruitment of specific proteins to form small nucleolar ribonucleoprotein particles (snoRNPs).
   • The mature box C/D snoRNA is generated by endonucleolytic cleavage at specific sites within the primary transcript, guided by the snoRNP complex.
2. Box H/ACA snoRNAs:
   • Box H/ACA snoRNAs have a characteristic hairpin-hinge-hairpin-tail structure, along with conserved H (ANANNA) and ACA boxes.
   • Processing of box H/ACA snoRNAs involves the assembly of a snoRNP complex, similar to box C/D snoRNAs.
   • The mature box H/ACA snoRNA is generated through endonucleolytic cleavage, guided by the assembled snoRNP complex.
3. Chemical Modifications:
   • Post-processing, mature snoRNAs guide the modification of target RNAs, predominantly rRNA. Box C/D snoRNAs guide 2′-O-methylation, while box H/ACA snoRNAs guide pseudouridylation.
   • These modifications influence the structural and functional properties of target RNAs, particularly in the context of ribosome biogenesis.

Quality Control Mechanisms:

The processing of snoRNAs is subject to quality control mechanisms to ensure the fidelity of the final products. Quality control involves surveillance mechanisms that detect and eliminate defective or aberrant Small Nucleolar RNA (snoRNA) species, preserving the integrity of the cellular RNA landscape.

Biogenesis of Small Nucleolar RNA (snoRNA):

The biogenesis or the birth of small nucleolar RNAs (snoRNAs) marks a pivotal moment in the orchestration of cellular processes.

1. Genomic Origins:
   • SnoRNA biogenesis begins with the transcription of host genes that contain snoRNA sequences. These host genes can be protein-coding or non-coding, and the snoRNA sequences may be located within introns.
   • Transcription of these host genes, often facilitated by RNA polymerase II, generates primary transcripts that serve as the precursors for snoRNAs.
2. Formation of snoRNA Precursors:
   • The primary transcripts undergo processing steps to form Small Nucleolar RNA (snoRNA) precursors. These precursors retain conserved structural motifs such as boxes C/D or H/ACA, depending on the class of snoRNA.
   • For box C/D snoRNAs, the precursor contains boxes C (UGAUGA) and D (CUGA), while box H/ACA snoRNA precursors exhibit a hairpin-hinge-hairpin-tail structure with conserved H (ANANNA) and ACA boxes.
3. Guided Cleavage and snoRNP Assembly:
   • The processing of Small Nucleolar RNA (snoRNA) precursors involves guided cleavage events that generate mature snoRNAs. This cleavage is often directed by the presence of conserved motifs within the precursor.
   • Post-cleavage, mature snoRNAs associate with specific proteins to form small nucleolar ribonucleoprotein particles (snoRNPs). These proteins contribute to the stability and functionality of snoRNAs.
4. Nuclear Transport:
   • The assembled snoRNPs are transported to the nucleolus, a specialized subnuclear compartment where ribosomal RNA (rRNA) processing predominantly occurs.
   • The nucleolus provides a conducive environment for snoRNA-guided modifications, particularly in the context of ribosome biogenesis.
5. Guiding Modifications:
   • Once in the nucleolus, snoRNAs guide specific chemical modifications, such as 2′-O-methylation (for box C/D snoRNAs) or pseudouridylation (for box H/ACA snoRNAs), onto target RNAs.
   • These modifications influence the structural and functional properties of the target RNAs, contributing to processes like ribosome maturation.
6. Quality Control Mechanisms:
   • Throughout snoRNA biogenesis, quality control mechanisms ensure the fidelity of the process. Surveillance systems detect and eliminate defective or aberrant snoRNA species, maintaining the integrity of the cellular RNA landscape.

Small Nucleolar RNA (snoRNA) are unassuming yet indispensable molecules serve as guides, directing specific chemical modifications on ribosomal RNA (rRNA), transfer RNA (tRNA), and other small nuclear RNAs (snRNAs). As guardians of cellular integrity, snoRNAs contribute to the fine-tuning of essential cellular functions, including ribosome biogenesis, splicing, and overall RNA maturation. This exploration into the realm of snoRNAs unveils their significance in the intricate orchestration of cellular processes, shedding light on the dynamic interplay between these diminutive molecules and the broader landscape of genetic regulation.

The small interfering RNA (siRNA) is a short RNA molecules, typically 20-25 base pairs in length, plays a pivotal role in the regulation of gene expression by guiding sequence-specific degradation of complementary mRNA. Discovered in the early 2000s, siRNA has rapidly emerged as a cornerstone in the field of RNA interference (RNAi), unlocking new possibilities in therapeutic applications, functional genomics, and the elucidation of intricate cellular processes.

The Full Form of siRNA:

In the realm of molecular biology, the acronym siRNA stands for Small Interfering RNA (siRNA). This compact yet powerful molecule has become a cornerstone in the field, serving as a crucial player in the intricate symphony of gene regulation.

The ‘S’ in siRNA denotes ‘small,’ emphasizing the diminutive size of these RNA molecules, typically comprising 20 to 25 nucleotide base pairs. Their compact nature belies their significant impact on cellular processes.

The ‘i’ in siRNA stands for ‘interfering,’ highlighting its role in the interference of gene expression. SiRNA interferes with the normal flow of genetic information within cells, executing its function with remarkable precision.

Lastly, ‘RNA’ signifies ‘ribonucleic acid,’ underscoring the molecular composition of siRNA. As a type of RNA, siRNA is intricately involved in the intricate dance of genetic regulation, orchestrating the selective silencing of specific genes.

Structure of small interfering RNA (siRNA):

The small interfering RNA (siRNA) is a molecular powerhouse in the realm of genetic regulation, boasting a distinct structure that serves as the foundation for its exceptional functionality.

Composition of small interfering RNA (siRNA):

• Double-Stranded Configuration: SiRNA is a double-stranded RNA molecule, typically comprising 20 to 25 nucleotide base pairs.
• Guide and Passenger Strands: The duplex consists of two strands – the guide strand, essential for target recognition and silencing, and the passenger strand, typically degraded.
• Sequence Specificity: SiRNA achieves its gene silencing specificity through the complementary pairing between the guide strand and the target mRNA.

Formation of small interfering RNA (siRNA):

• RNA Interference (RNAi): SiRNA is derived from larger precursor molecules, such as long double-stranded RNA (dsRNA) or small hairpin RNA (shRNA).
• Dicer Enzyme: The Dicer enzyme plays a pivotal role, cleaving the precursor molecules into smaller fragments, which are then processed into the characteristic 20-25 base pair duplex.
• 3′ Overhangs: SiRNA features 3′ overhangs, contributing to structural stability and determining which strand is preferentially selected as the guide strand during incorporation into the RNA-induced silencing complex (RISC).

Three-Dimensional Architecture of small interfering RNA (siRNA):

• A-Form Helical Structure: The duplex adopts an A-form helical structure, where the sugar-phosphate backbone twists around a central axis.
• 3′ Overhangs Significance: The 3′ overhangs, dangling at one end of the duplex, enhance structural stability and integrity.
• Interactions with Argonaute Protein: Within the RISC complex, the guide strand forms intricate interactions with the Argonaute protein, shaping the overall architecture and facilitating precise target mRNA recognition.

Significance of Structure in Genetic Regulation:

• Structural Features and Functional Precision: The A-form helix, 3′ overhangs, and asymmetric selection of the guide strand collectively contribute to the biological function of siRNA.
• Selective Loading into RISC: The selective loading of the guide strand into the RISC complex underscores the importance of structural asymmetry in determining which strand guides the silencing machinery.

If you want to know about the snRNA then read the article: The Structure and Function of Small Nuclear RNA (snRNA).

The function of small interfering RNA (siRNA):

Small Interfering RNA (siRNA) serves as a molecular maestro in the orchestra of genetic regulation, orchestrating the silencing of specific genes with unparalleled precision.

Gene Silencing Precision:

• Sequence-Specific Targeting: SiRNA achieves gene silencing through its ability to selectively target mRNA sequences that are complementary to its guide strand.
• RNA-Induced Silencing Complex (RISC): Upon entering the cytoplasm, siRNA is incorporated into the RISC, a molecular machinery that guides the guide strand to its complementary mRNA, marking it for degradation.
• Cleavage of mRNA: The guide strand within the RISC complex catalyzes the cleavage of the target mRNA, preventing its translation into protein.

Biogenesis and Cellular Entry:

• RNA Interference (RNAi) Pathway: SiRNA is a product of the RNA interference pathway, initiated by the enzymatic cleavage of long double-stranded RNA (dsRNA) or small hairpin RNA (shRNA) by Dicer.
• Dicer Processing: Dicer processes the precursor molecules into siRNA duplexes, which are then loaded onto the RISC complex.
• Cellular Uptake: SiRNA, often introduced exogenously, can be taken up by cells through various delivery methods, allowing for the targeted regulation of specific genes.

Offensive Against Viruses and Transposons:

• Antiviral Defense Mechanism: SiRNA plays a crucial role in the defense against viral infections by recognizing and targeting viral RNA, inhibiting viral replication.
• Transposon Suppression: SiRNA is involved in suppressing the activity of transposable elements within the genome, maintaining genomic stability.

Therapeutic Applications:

• Precision Medicine: SiRNA offers a highly specific approach to treating diseases by selectively silencing disease-related genes, paving the way for personalized and targeted therapies.
• Cancer Treatment: SiRNA has promising applications in cancer therapy by targeting and silencing oncogenes or genes involved in tumor progression.

Limitations and Challenges:

• Off-Target Effects: SiRNA’s exquisite specificity can sometimes be compromised by off-target effects, necessitating careful design and optimization.
• Delivery Challenges: Efficient delivery of siRNA to target cells remains a hurdle in therapeutic applications, requiring innovative delivery strategies.

If you want to know about snoRNA then read the article: Structure and Function of Small Nucleolar RNA (snoRNA).

The siRNA-Mediated Gene Silencing:

Small interfering RNA (siRNA) has emerged as a potent tool in molecular biology, offering a precise mechanism for manipulating gene expression. SiRNA-mediated gene silencing involves a sophisticated process through which specific genes are selectively and effectively turned off at the molecular level.

SiRNA-mediated gene silencing is a mechanism by which the expression of a targeted gene is inhibited through the introduction of synthetic or endogenously produced siRNA molecules into a cell. SiRNA, typically 20-25 nucleotide base pairs in length, is designed to be complementary to the mRNA sequence of the target gene. Once introduced into the cell, siRNA guides the RNA-induced silencing complex (RISC) to recognize and bind to the corresponding mRNA.

If you want to know the differences between the snRNA and snoRNA then read the article: Differences Between snRNAs and snoRNAs.

The siRNA Biogenesis:

Small interfering RNA (siRNA) biogenesis is a tightly regulated and intricate process crucial for the precision of gene regulation within cells. This journey commences with the introduction of exogenous double-stranded RNA (dsRNA) or the formation of endogenous hairpin structures, serving as the initial precursor molecules. The pivotal enzyme Dicer takes center stage, cleaving these precursors into short RNA duplexes of approximately 20-25 base pairs. Among the resulting fragments, one strand is selected as the guide strand, while the other becomes the passenger strand.

The siRNA Technology:

The small interfering RNA (siRNA) technology stands at the forefront of molecular innovation, offering a versatile and precise approach to gene modulation. Let’s explore the key features and applications of this revolutionary technology through concise bullet points:

Design and Synthesis:

• Custom-designed synthetic siRNAs or endogenously produced siRNAs.
• Typically 20-25 nucleotide base pairs in length.
• Engineered to target specific mRNA sequences with high specificity.

Initiation of RNA Interference (RNAi) Pathway:

• Introduction of designed siRNAs into cells.
• Activation of the cell’s natural RNAi pathway.

Mechanism of Action:

• Cleavage of targeted mRNA by the RNA-induced silencing complex (RISC).
• Degradation or translational repression of mRNA.
• Precise gene silencing without altering the DNA sequence.

Applications in Research:

• Facilitates functional genomics research.
• Enables selective gene silencing for understanding cellular processes.
• Unravels gene functions with unparalleled specificity.

Diagnostic Potential:

• Identifying and validating potential therapeutic targets.
• Offers insights into disease mechanisms.
• Precision in disease diagnostics through gene expression modulation.

Therapeutic Promise:

• Targeting genetic disorders, viral infections, and cancer.
• Highly personalized treatment approach.
• Potential for innovative medical interventions.

Clinical Trials and Research Initiatives:

• Active exploration of therapeutic potential.
• Ongoing studies to validate safety and efficacy.
• Promising results shaping the future of clinical applications.

Challenges and Ongoing Research:

• Addressing efficient delivery methods.
• Minimizing off-target effects.
• Continuous refinement of small interfering RNA (siRNA) design for enhanced safety.

The small interfering RNA (siRNA) stands at the forefront of revolutionary advancements in molecular biology, offering a powerful tool to manipulate gene expression with unparalleled precision.

The microRNA (miRNA) represents a fascinating class of small non-coding RNA molecules that play a pivotal role in the intricate regulatory networks governing gene expression. The microRNA (miRNA) is a short RNA sequence, typically consisting of 20-22 nucleotides and exerts influence at the post-transcriptional level.

The full form of miRNA:

The miRNAs constitute a class of small, non-coding RNA molecules that play pivotal roles in regulating gene expression. Despite their diminutive size, miRNAs exert significant influence over a multitude of biological processes. The term “miRNA” itself stands for “Micro Ribonucleic Acid,” reflecting its short nucleotide length and its classification as a type of RNA.

What is microRNA (miRNA):

The journey of miRNA begins in the nucleus, where primary miRNA transcripts are transcribed from specific genes by RNA polymerase II. These primary transcripts, known as pri-miRNAs, fold into hairpin structures. The microprocessor complex, comprising the RNase III enzyme Drosha and its cofactor DGCR8, then cleaves the pri-miRNA to yield precursor miRNAs (pre-miRNAs). Pre-miRNAs are subsequently transported to the cytoplasm by Exportin-5, where the RNase III enzyme Dicer processes them into mature miRNAs. The resulting mature miRNA is incorporated into the RNA-induced silencing complex (RISC), setting the stage for its regulatory functions.

If you want to know about siRNA then read the article: Structure and Function of small interfering RNA (siRNA).

The structure of microRNA (miRNA):

The microRNA (miRNA) are small RNA molecules with a remarkably intricate structure that belies their substantial regulatory impact on gene expression. The structure of miRNAs is a key factor in understanding their function and versatility in orchestrating various cellular processes.

At its core, a typical miRNA molecule is composed of approximately 20 to 22 nucleotides. Nucleotides are the building blocks of RNA and DNA, and in miRNAs, they form a single-stranded chain. The structure of a miRNA can be divided into specific regions, each with its own functional significance.

1. Seed Region: The seed region, typically comprising nucleotides 2-8 at the 5′ end of the miRNA, is a critical determinant of target recognition. This region serves as a guide for the miRNA to identify and bind to complementary sequences in the messenger RNA (mRNA) of target genes.
2. Mature Region: This encompasses the entire length of the miRNA and includes the seed region. The mature region is essential for the interaction with the RNA-induced silencing complex (RISC), a molecular machinery that facilitates the silencing or degradation of target mRNAs.
3. 5′ and 3′ Ends: The 5′ and 3′ ends of the miRNA play roles in stability and processing. The 5′ end often undergoes post-transcriptional modifications, while the 3′ end contributes to the precision of target recognition.
4. Hairpin Structure: Before miRNAs mature into their functional form, they are initially transcribed as long precursor molecules, known as primary miRNAs (pri-miRNAs). These pri-miRNAs fold into hairpin structures, which are then processed in the nucleus to form precursor miRNAs (pre-miRNAs), and further processed in the cytoplasm to generate the mature, functional miRNA.

If you want to know about the gene silencing then read the article: What is Gene Silencing | Types, Mechanisms, Examples and Uses.

The function of microRNA (miRNA):

Despite their small size, typically consisting of 20-22 nucleotides, microRNA (miRNA) wield significant influence over the intricate dance of genetic information, contributing to the fine-tuning of cellular functions and maintaining homeostasis.

The primary function of microRNA (miRNA) lies in their ability to modulate gene expression at the post-transcriptional level. This regulatory prowess is executed through a series of intricately choreographed steps:

1. Target Recognition: MiRNAs recognize and bind to specific messenger RNA (mRNA) molecules, guided by a complementary sequence within the miRNA, particularly in its seed region (nucleotides 2-8). This interaction occurs within the RNA-induced silencing complex (RISC), a molecular machinery that serves as the conductor of the miRNA symphony.
2. Gene Silencing: Once bound to their target mRNA, miRNAs can enact gene silencing through two main mechanisms. They can either inhibit the translation of the mRNA into protein, or they can induce the degradation of the mRNA molecule. By interfering with these crucial steps, miRNAs act as molecular brakes, modulating the expression levels of their target genes.
3. Regulation of Development and Differentiation: MiRNAs play a central role in developmental processes and cellular differentiation. They contribute to the precision and timing of developmental events by regulating the expression of genes involved in these processes. This involvement is particularly crucial during embryogenesis, where miRNAs sculpt the blueprint of an organism.
4. Response to Environmental Stimuli: Cells rely on miRNAs to swiftly adapt to changing environmental conditions and stressors. MiRNAs can be dynamically regulated in response to various signals, influencing the cellular response to stress, nutrient availability, and other external cues.
5. Disease Implications: Dysregulation of miRNAs is associated with a spectrum of diseases, including cancer, cardiovascular disorders, neurodegenerative diseases, and immune-related conditions. Some miRNAs act as oncogenes, promoting tumor growth, while others function as tumor suppressors, inhibiting uncontrolled cell proliferation.

The Biogenesis of microRNA (miRNA):

MicroRNA (miRNA) biogenesis is a highly regulated and orchestrated process that transforms genetic information into functional RNA molecules.

• The journey begins with transcription in the cell nucleus, where RNA polymerase II synthesizes primary miRNA transcripts (pri-miRNAs).
• These pri-miRNAs, often embedded in gene introns, undergo processing by the Drosha-DGCR8 complex, forming hairpin-shaped precursor miRNAs (pre-miRNAs).
• Exportin-5 transports pre-miRNAs to the cytoplasm, where Dicer, in collaboration with partner proteins, cleaves them into short double-stranded RNA duplexes.
• The mature miRNA strand is then loaded onto the miRNA-induced silencing complex (RISC). Guided by the mature miRNA, RISC identifies and binds to complementary mRNA sequences, leading to translational repression or mRNA degradation.
• This precise and sequential biogenesis pathway highlights the sophistication of miRNA regulation in fine-tuning gene expression, with implications for various cellular processes and potential therapeutic interventions.

The Pathway of microRNA (miRNA):

The pathway of microRNA (miRNA) unveils a captivating journey within the cellular landscape, where these small RNA molecules navigate a meticulously regulated course to exert profound influence over gene expression. The miRNA pathway, often referred to as the miRNA biogenesis and silencing pathway, involves a series of finely tuned steps that commence in the nucleus and culminate in the cytoplasm, shaping the cellular symphony of genetic regulation.

1. Transcription: The journey kicks off with the transcription of miRNA genes by RNA polymerase II, generating primary miRNA transcripts (pri-miRNAs). These pri-miRNAs can be independent transcriptional products or can be nested within the introns of protein-coding genes.
2. Pri-miRNA Processing: In the nucleus, the enzyme complex Drosha-DGCR8 meticulously cleaves the pri-miRNAs, creating precursor miRNAs (pre-miRNAs) characterized by hairpin structures. This intricate haircutting process defines the initial form of miRNAs.
3. Export to Cytoplasm: Transported by Exportin-5, the pre-miRNAs travel from the nucleus to the cytoplasm, marking the transition from their birthplace to the site of their functional activity.
4. Dicing and Formation of Mature miRNA: Once in the cytoplasm, the pre-miRNAs encounter Dicer, a key enzyme accompanied by partner proteins. Dicer cleaves the pre-miRNAs into short double-stranded RNA duplexes. From this duplex, the mature miRNA strand is chosen to guide the miRNA-induced silencing complex (RISC).
5. Loading onto RISC: The mature miRNA is loaded onto the RISC, a versatile molecular machine that acts as the executioner of miRNA function. The RISC, guided by the mature miRNA, embarks on a quest to find specific mRNA targets based on sequence complementarity.
6. Target Binding and Regulation: The RISC identifies mRNA targets with complementary sequences to the mature miRNA. Once identified, the RISC either represses translation or induces degradation of the targeted mRNA, ultimately fine-tuning gene expression and influencing diverse cellular processes.

The microRNA (miRNA) Mediated Gene Silencing:

The microRNA (miRNA) mediated gene silencing is a sophisticated cellular process crucial for the fine-tuning of gene expression. The journey begins with the transcription of miRNA genes, generating primary miRNA transcripts (pri-miRNAs). These pri-miRNAs are processed in the nucleus by the Drosha-DGCR8 complex, yielding precursor miRNAs (pre-miRNAs) with characteristic hairpin structures. Transported to the cytoplasm, pre-miRNAs encounter Dicer, which cleaves them into mature miRNA duplexes. The mature miRNA strand is then loaded onto the miRNA-induced silencing complex (RISC), guiding RISC to target specific mRNA sequences.

In this exploration of microRNA (miRNA), we delve into their biogenesis, mechanisms of action, and the intricate web of interactions that govern their function. As we navigate this intricate landscape, the significance of miRNAs in shaping cellular dynamics becomes increasingly evident, underscoring their potential as diagnostic markers and therapeutic targets.