DNA, or deoxyribonucleic acid, is the molecule that carries the genetic blueprint of living organisms. Despite being extremely long—up to 2 meters in humans—DNA fits neatly into the nucleus of each cell, which is only about 6 micrometers in diameter. This incredible feat of biological engineering is achieved through a complex process known as DNA packaging in chromosome.

The Structure of DNA

Before diving into DNA packaging in chromosome, it’s essential to understand the structure of DNA. DNA is composed of two long strands forming a double helix. These strands are made up of nucleotides, each consisting of a sugar molecule, a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). The sequence of these bases encodes genetic information.

If you want to know the detailed structure of DNA and RNA then read the article: DNA and RNA Structure and Function | Structure and Function of Nucleic Acids.

Definition of DNA Packaging:

DNA packaging in chromosomes refers to the process by which long DNA molecules are compactly and efficiently organized within the cell nucleus. This involves winding the DNA around histone proteins to form nucleosomes, further coiling into chromatin fibers, and then looping and folding these fibers to create the highly condensed structure of a chromosome. This DNA packaging in chromosomes is not only fits DNA into the nucleus but also protects it, aids in gene regulation, and ensures accurate distribution during cell division.

DNA Packaging in Nucleus:

The site of DNA packaging in chromosome is inside the cell nucleus. The nucleus is a membrane-bound organelle found in eukaryotic cells, acting as the control center that houses most of the cell’s genetic material. Within the nucleus, DNA is packaged into structures called chromosomes, ensuring the DNA is efficiently managed and utilized.

Chromatin: The DNA-Protein Complex

Within the nucleus, DNA does not float freely. Instead, it is tightly associated with proteins to form chromatin. Chromatin exists in two forms:

• Euchromatin: Less condensed and transcriptionally active, meaning genes in these regions are more likely to be expressed.
• Heterochromatin: Highly condensed and transcriptionally inactive, meaning genes in these regions are generally not expressed.

Nuclear Organization and DNA Packaging

The nucleus is not a random mixture of DNA and proteins. Instead, it is highly organized, with specific regions dedicated to particular functions:

• Nucleolus: The site where ribosomal RNA (rRNA) is synthesized and ribosome assembly begins.
• Nuclear Envelope: A double membrane that encloses the nucleus, punctuated by nuclear pores that regulate the transport of molecules in and out of the nucleus.
• Nuclear Lamina: A network of intermediate filaments that provide structural support and organize chromatin.

Importance of DNA Packaging in the Nucleus

Proper DNA packaging in chromosome within the nucleus is essential for several reasons:

• Efficient Storage: Allows long DNA molecules to fit within the tiny nucleus.
• Protection: Shields DNA from physical and chemical damage.
• Gene Regulation: Controls which genes are accessible for transcription, thereby regulating gene expression.
• Facilitation of Cell Division: Ensures that chromosomes are compact and manageable during mitosis and meiosis, leading to accurate genetic material distribution.

Process of DNA Packaging:

The process of DNA packaging in chromosomes is a testament to the efficiency and complexity of biological systems. By transforming long DNA strands into compact chromosomes, cells can manage genetic information effectively, ensuring protection, regulation, and precise distribution during cell division.

Steps of DNA Packaging

1. Formation of Nucleosomes

The first level of DNA packaging in chromosome involves wrapping DNA around histone proteins. Histones are positively charged proteins that help neutralize the negatively charged DNA, allowing it to coil tightly. Eight histone proteins form a core particle, and DNA wraps around this core about 1.65 times, creating a nucleosome. This structure resembles beads on a string, with DNA as the string and nucleosomes as the beads, reducing the DNA length by about seven times.

2. Creating Chromatin Fibers

The nucleosomes further coil and stack on top of each other to form chromatin fibers, often referred to as “30 nm fibers” due to their diameter. Histone H1 plays a crucial role in stabilizing these fibers. This level of compaction further reduces the DNA length significantly, making it about 50 times shorter than its original length.

3. Looping and Scaffolding

The chromatin fibers then loop and attach to a protein scaffold within the nucleus, forming looped domains. These loops bring distant parts of the DNA into close proximity, which is essential for the regulation of gene expression and efficient organization. This step further condenses the DNA.

4. Supercoiling into Chromosomes

During cell division, the chromatin fibers undergo even more compaction to form the highly condensed structures known as chromosomes. Each chromosome consists of a single, continuous DNA molecule. In its most condensed form, a chromosome is about 10,000 times shorter than its extended length. Human cells typically contain 46 chromosomes, organized into 23 pairs.

DNA Packaging in Prokaryotes

DNA packaging in chromosome is a crucial process that ensures the genetic material is organized, protected, and efficiently used by the cell. While much attention is often given to the complex DNA packaging mechanisms in eukaryotes, prokaryotes, such as bacteria and archaea, also have sophisticated methods for organizing their DNA.

Prokaryotic Cell Structure

Prokaryotic cells are generally simpler and smaller than eukaryotic cells. They lack a nucleus and membrane-bound organelles. Instead, their genetic material is located in a region called the nucleoid, which is not enclosed by a membrane.

The Prokaryotic Genome

Prokaryotic DNA is typically a single, circular chromosome, although some species may have linear chromosomes or multiple chromosomes. In addition to the main chromosome, prokaryotes often contain smaller, circular DNA molecules called plasmids, which carry extra genetic information beneficial for survival, such as antibiotic resistance genes.

Steps of DNA Packaging in Prokaryotes

1. Supercoiling

The primary method of DNA packaging in chromosome of prokaryotes is supercoiling. Supercoiling involves twisting the DNA molecule to make it more compact. There are two types of supercoiling:

• Positive Supercoiling: The DNA is twisted in the same direction as the double helix, making it more tightly wound.
• Negative Supercoiling: The DNA is twisted in the opposite direction, making it underwound. Negative supercoiling is more common in prokaryotes because it helps in the unwinding of the double helix for processes like replication and transcription.

Topoisomerases are enzymes that manage DNA supercoiling. They introduce or remove supercoils by cutting one or both strands of the DNA, allowing it to unwind or rewind, and then resealing the breaks.

2. Nucleoid-Associated Proteins (NAPs)

Prokaryotes use proteins called nucleoid-associated proteins (NAPs) to further organize and compact their DNA. These proteins bind to DNA and induce bending, bridging, and compaction. Some key NAPs include:

• HU: Binds to DNA and introduces bends, helping to compact the chromosome.
• FIS: Involved in DNA compaction and regulation of gene expression.
• H-NS: Helps to compact DNA and is involved in gene silencing by binding to specific regions of the genome.

3. DNA Gyrase

DNA gyrase, a type of topoisomerase, introduces negative supercoils into DNA using the energy from ATP. This enzyme is crucial for maintaining the supercoiled state of the prokaryotic genome, which is necessary for efficient packaging and accessibility of DNA.

4. Macrodomain Organization

The prokaryotic chromosome is further organized into regions called macrodomains. Each macrodomain contains segments of the chromosome that are spatially distinct from other regions. This organization helps in the regulation of DNA replication, segregation, and gene expression.

Plasmid Packaging

In addition to the main chromosome, many prokaryotes carry plasmids. Plasmids are small, circular DNA molecules that replicate independently of the chromosomal DNA. They are usually not as tightly packed as the chromosomal DNA but still require some degree of supercoiling and protein association for efficient function and stability.

Watch the DNA packaging in chromosome here.

Importance of DNA Packaging in Prokaryotes

Proper DNA packaging in prokaryotes is essential for several reasons:

• Efficient Storage: Compaction allows the large DNA molecule to fit within the small cell.
• Protection: Tightly packed DNA is protected from damage.
• Regulation of Gene Expression: Organized DNA helps control which genes are accessible for transcription.
• Facilitation of Cellular Processes: Efficient DNA packaging is crucial for DNA replication, segregation during cell division, and repair processes.

DNA Packaging in Eukaryotes

Eukaryotic cells, which include plants, animals, fungi, and protists, have a more complex organization compared to prokaryotic cells. One of the most remarkable aspects of this complexity is how eukaryotic cells manage to package their lengthy DNA molecules into the tiny confines of the cell nucleus. This process is crucial for maintaining the integrity of genetic information and ensuring its proper utilization.

DNA and the Nucleus

Eukaryotic DNA is organized into structures called chromosomes, which are housed within the nucleus—a membrane-bound organelle. Each eukaryotic species has a specific number of chromosomes that carry its genetic information. For example, humans have 46 chromosomes.

The Levels of DNA Packaging

1. Nucleosomes: The Basic Units

The first level of DNA packaging in chromosome involves the formation of nucleosomes. DNA wraps around histone proteins to form these structures. Specifically, 147 base pairs of DNA wind around a histone octamer, composed of two each of the histone proteins H2A, H2B, H3, and H4. This creates a “beads-on-a-string” structure, with nucleosomes as the beads and DNA as the string, reducing the DNA length by about seven times.

2. 30 nm Fiber: Higher-Order Structure

The nucleosome chain further coils into a thicker fiber, known as the 30 nm fiber, due to its diameter. Histone H1 plays a crucial role in stabilizing this structure by binding to the DNA at the entry and exit points of the nucleosome, facilitating tighter packing. This level of organization compacts the DNA even further.

3. Loop Domains: Functional Compaction

The 30 nm fibers then form loops, which are attached to a protein scaffold within the nucleus. These loops, known as loop domains, bring distant regions of DNA into proximity, enabling efficient regulation of gene expression and DNA replication. These loops can be several hundred thousand base pairs long, significantly reducing the overall length of the DNA.

4. Chromatin and Chromosomes: Ultimate Condensation

During cell division, the chromatin fibers undergo extreme condensation to form chromosomes. Each chromosome consists of one long DNA molecule, which is further coiled and folded to achieve a highly compact structure. This supercoiling makes the chromosomes visible under a light microscope and ensures the genetic material is efficiently separated into daughter cells.

Role of Epigenetics in DNA Packaging

DNA packaging in chromosome is not just about fitting DNA into the nucleus; it also plays a critical role in gene regulation. Epigenetic modifications, such as such as the addition of chemical groups to histones or DNA itself, can alter the packaging state like methylation of DNA and acetylation of histones, can alter the packing density of chromatin. These modifications can either loosen or tighten DNA packaging in chromosome, thereby controlling the accessibility of genes for transcription and influencing gene expression without altering the DNA sequence itself.

Importance of DNA Packaging

• Efficient Storage: Compaction allows the vast amount of DNA to fit within the small nucleus.
• Protection: Tightly packed DNA is less susceptible to damage.
• Regulation of Gene Expression: DNA packaging controls which genes are accessible for transcription, thereby regulating cellular functions.
• Facilitation of Cell Division: Properly packaged DNA ensures accurate segregation during mitosis and meiosis, preventing genetic disorders.

DNA packaging in chromosomes is a remarkable example of nature’s ingenuity, allowing vast amounts of genetic information to be efficiently stored, protected, and regulated within the tiny space of a cell nucleus.

FAQ on DNA Packaging in Chromosomes

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:

Biology Full Forms List

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

Watch The Video of Biology Full Forms Here

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.

The process of converting ATP to cAMP involves the removal of two phosphate groups from ATP, resulting in the formation of cAMP with a cyclic structure. cAMP acts as a second messenger in intracellular signal transduction pathways, relaying information from extracellular signals to the cell’s interior.

The main function of cAMP is to activate protein kinase A (PKA), an enzyme that phosphorylates various target proteins. Phosphorylation, the addition of a phosphate group to a protein, is a crucial regulatory mechanism that can influence the activity, localization, and interactions of the targeted proteins. By activating PKA and subsequently phosphorylating specific proteins, adenylate cyclase plays a role in regulating a wide range of cellular processes, including:

1. Cellular metabolism: cAMP can influence enzymes involved in metabolic pathways, altering cellular energy production and consumption.
2. Hormone signaling: Adenylate cyclase is involved in the signal transduction pathways of various hormones, such as adrenaline (epinephrine), glucagon, and several others.
3. Neurotransmission: cAMP signaling is essential in many aspects of neuronal function and communication.
4. Ion channel regulation: cAMP can influence the opening and closing of ion channels, affecting the cell’s electrical excitability.

Adenylate cyclase is subject to regulation by various mechanisms, including G protein-coupled receptors (GPCRs), which are a large family of cell surface receptors involved in transmitting signals from hormones and neurotransmitters to the inside of the cell. GPCRs activate adenylate cyclase indirectly through G proteins, which act as molecular switches.

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.

Related to this biology full forms, you can read more about DNA in this article: What are the monomers of DNA and RNA | Name, Example and Structure

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. 

FAQ on Biology Full Forms

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. So it is important to know the differences between genetic diversity, species diversity, and ecosystem diversity.

If you want to know about the living world then read the article: What is Living | Differences Between Living and Non-Living.

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.

In the realm of biodiversity, three key components play vital roles: genetic diversity, species diversity, and ecosystem diversity. Each of these aspects contributes to the intricate web of life on Earth, but they differ in their scope and significance. Differences between genetic diversity, species diversity, and ecosystem diversity, highlighting their unique characteristics and importance in maintaining a healthy and balanced environment.

Genetic Diversity

Definition: Genetic diversity refers to the variation in genes within a particular species. This includes differences in DNA among individuals of the same species and between populations of the same species.

Importance: Genetic diversity is crucial for the survival and adaptability of a species. Higher genetic variation within a species increases the likelihood that some individuals will possess traits that allow them to survive and reproduce in changing environmental conditions. This adaptability can lead to a species’ long-term survival.

Example: Consider a population of wolves. Genetic diversity within this population might include variations in coat color, resistance to diseases, and hunting skills. These genetic differences help the wolf population adapt to various challenges and environments.

Species Diversity

Definition: Species diversity refers to the variety of species within a particular region or ecosystem. It considers both the number of different species (species richness) and the abundance of each species (species evenness).

Importance: High species diversity contributes to ecosystem resilience, productivity, and stability. Diverse ecosystems are better able to withstand environmental stress and are more productive due to the variety of functions performed by different species.

Example: A coral reef is a prime example of high species diversity. It hosts a wide array of species, including various types of fish, corals, mollusks, and crustaceans, each contributing to the reef’s overall health and functionality.

Ecosystem Diversity

Definition: Ecosystem diversity refers to the variety of ecosystems in a particular area. This includes the different biological communities and their interactions with the physical environment.

Importance: Ecosystem diversity ensures the availability of multiple habitats, allowing different species to thrive and interact. It also supports a wide range of ecological processes and services, such as nutrient cycling, water purification, and climate regulation.

Example: Ecosystem diversity can be seen in a region that includes forests, wetlands, grasslands, and deserts. Each of these ecosystems provides unique habitats and supports different communities of organisms, contributing to the overall biodiversity of the area.

Comparing the Three Types of Diversity

1. Scope:
   • Genetic Diversity focuses on the variety of genes within a single species.
   • Species Diversity considers the variety of species within a particular habitat or region.
   • Ecosystem Diversity encompasses the variety of ecosystems within a larger geographic area.
2. Role in Adaptability:
   • Genetic Diversity enhances the adaptability of species to changing conditions.
   • Species Diversity contributes to the resilience and stability of ecosystems.
   • Ecosystem Diversity ensures the availability of diverse habitats and ecological processes.
3. Examples:
   • Genetic Diversity: Different fur colors in a wolf population.
   • Species Diversity: Various species in a coral reef.
   • Ecosystem Diversity: Forests, wetlands, and deserts in a single region.

Differences between genetic diversity, species diversity, and ecosystem diversity

Aspect	Genetic Diversity	Species Diversity	Ecosystem Diversity
Definition	Variation in genes within a single species.	Variety of species within a particular region.	Variety of ecosystems within a larger geographic area.
Scope	Focuses on genetic differences among individuals and populations of a single species.	Considers the number and abundance of different species in an area.	Encompasses the variety of ecosystems and their interactions within a region.
Importance	Enhances a species’ ability to adapt to changing conditions and survive long-term.	Contributes to ecosystem resilience, productivity, and stability.	Ensures the availability of diverse habitats and supports a range of ecological processes.
Role in Adaptability	Increases the likelihood of survival and reproduction in changing environments.	Helps ecosystems withstand environmental stress and function effectively.	Provides diverse habitats and supports multiple ecological functions.
Examples	Different fur colors, disease resistance, and hunting skills within a wolf population.	Various species in a coral reef, like fish, corals, and mollusks.	Forests, wetlands, grasslands, and deserts within a single region.
Impact on Biodiversity	Affects the genetic health and evolutionary potential of a species.	Influences the richness and evenness of species in an ecosystem.	Determines the complexity and range of ecosystems and their interactions.

Differences between genetic diversity, species diversity, and ecosystem diversity are intricately interconnected and play critical roles in maintaining the delicate balance of life on Earth. Genetic diversity enables species to adapt and evolve, while species diversity ensures the resilience and stability of ecosystems. Ecosystem diversity, in turn, provides essential services and supports the well-being of all living organisms. Recognizing and valuing these distinct aspects of biodiversity is essential for effective conservation, sustainable development, and the preservation of our planet’s rich natural heritage.

FAQ on Differences between genetic diversity, species diversity, and ecosystem diversity

What is Living 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.

What is Living?

Living entities, often referred to as organisms, are the fundamental units of life on Earth. They exhibit a variety of characteristics that distinguish them from non-living matter. Understanding what makes something “living” involves exploring several key attributes that all living organisms share.

Characteristics of Living Things

1. Cellular Organization
   • All living things are composed of cells, which are the basic units of life. Cells can be unicellular (single-celled) like bacteria, or multicellular (many cells) like plants and animals. Each cell performs vital functions that contribute to the organism’s survival.
2. Metabolism
   • Metabolism encompasses all the chemical reactions that occur within an organism. These reactions are necessary for maintaining life, allowing organisms to grow, reproduce, repair damage, and respond to their environment. Metabolism involves both anabolism (building up) and catabolism (breaking down) processes.
3. Growth and Development
   • Living organisms undergo growth, an increase in size and often in number of cells. Development refers to the changes in the organism’s life cycle, from its origin to its adult form. This process is guided by the organism’s genetic information.
4. Reproduction
   • Reproduction is the biological process by which new individual organisms are produced. It can be asexual, involving a single organism, or sexual, involving the combination of genetic material from two organisms. Reproduction ensures the continuity of species.
5. Response to Stimuli
   • All living things can respond to their environment. This characteristic, known as irritability, involves reacting to physical or chemical changes in the surroundings. For example, plants grow towards light, and animals may flee from danger.
6. Homeostasis
   • Homeostasis is the ability of an organism to maintain a stable internal environment despite changes in external conditions. This includes regulating temperature, pH levels, and other vital functions to keep the organism’s internal environment within a certain range.
7. Adaptation through Evolution
   • Over time, living organisms undergo evolution, a process where inherited characteristics change across generations. This enables organisms to adapt to their environment, improving their chances of survival. Evolution is driven by natural selection, genetic drift, mutations, and gene flow.

Picture of Living Things

The Building Blocks of Life

Living organisms are made up of various elements and compounds, primarily carbon, hydrogen, oxygen, and nitrogen. These elements combine to form molecules essential for life, such as proteins, lipids, carbohydrates, and nucleic acids. These molecules play critical roles in the structure and function of cells.

1. Proteins: Made of amino acids, they perform numerous functions including catalyzing metabolic reactions, replicating DNA, and transporting molecules.
2. Lipids: These include fats and oils, which store energy and make up cell membranes.
3. Carbohydrates: These provide energy and structural support.
4. Nucleic Acids: DNA and RNA, which store and transmit genetic information.

The Diversity of Life

The living world is incredibly diverse, encompassing a wide range of organisms from the simplest bacteria to the most complex plants and animals. This diversity is categorized into various levels of biological classification: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. Each level groups organisms based on shared characteristics and evolutionary history.

1. Domains: The broadest classification, including Archaea, Bacteria, and Eukarya.
2. Kingdoms: Further division within domains, such as Animalia, Plantae, Fungi, Protista, Archaea, and Bacteria.

Read Here: Biological Classification Taxonomy Class 11 Full Chapter 2 in Gist

What is Non-Living?

Non-living things encompass everything in our universe that does not exhibit the characteristics of life. Unlike living organisms, non-living entities do not grow, reproduce, respond to stimuli, or maintain homeostasis. They can be natural, like rocks and water, or man-made, like buildings and computers. Understanding what constitutes non-living helps us appreciate the differences between the animate and inanimate components of our world.

What is living visit here

Differences Between Living and Non-Living Things

Picture of Living and Non-Living

Characteristic	Living Things	Non-Living Things
Cellular Organization	Composed of one or more cells, which are the basic units of life	Do not have cells
Metabolism	Exhibit metabolic processes such as respiration and digestion	Do not have metabolic processes
Growth	Grow by increasing in size and/or number of cells	Do not grow; may change in size due to external factors (e.g., erosion)
Reproduction	Capable of reproducing to create new individuals	Cannot reproduce
Response to Stimuli	Respond to environmental changes and stimuli	Do not respond to stimuli
Homeostasis	Maintain a stable internal environment	Do not regulate internal conditions
Adaptation through Evolution	Adapt to their environment over time through evolution	Do not evolve or adapt
Movement	Can move on their own, either the whole organism or parts of it (e.g., cells)	Do not move on their own; may be moved by external forces
Energy Use	Use energy for growth, maintenance, and activities	Do not use energy
Lifespan	Have a definite lifespan, after which they die	Do not have a lifespan; exist indefinitely unless destroyed
Complexity	Highly complex and organized at both molecular and cellular levels	Typically simpler and lack organized structures found in living things
Composition	Made of organic compounds like proteins, lipids, carbohydrates, and nucleic acids	Composed of inorganic materials and sometimes organic materials

FAQ on What is Living

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:

At the heart of every protein lies a chain of amino acids meticulously arranged in a specific sequence. It is the sequence, arrangement, and properties of amino acids that determine the structure and function of the resulting protein. Amino acids exhibit a remarkable diversity in their chemical structures, owing to the variability of their side chains. This structural diversity enables proteins to carry out the functions in living organisms.

Definition of Amino Acids:

Amino acids are organic acids that serve as the fundamental building blocks of proteins, essential for the structure, function, and regulation of living organisms.

In biochemistry, amino acids stand as the fundamental units that explain the complexity of life. The structure and the properties of amino acids are important to understanding their role as the building blocks of proteins and their significance in biological processes.

Structure of Amino Acids:

1. Structurally, amino acids consist of a central carbon atom (the alpha carbon) bonded to a hydrogen atom, an amino group (NH2), a carboxyl group (COOH), and a unique side chain (R group).
2. It is this side chain that distinguishes one amino acid from another, imparting specific chemical, functionalities and the properties of amino acids.
3. The distinguishing feature of each amino acid is its unique side chain, or R group, which confers specific chemical properties to the amino acid.
4. The twenty different amino acids found in proteins vary in their side chains, leading to a wide range of chemical characteristics and functionalities.

The amino acids play a crucial role in biological systems to determine the relationship between protein structure and function.

● When amino acids are linked together through peptide bonds (a chemical linkage between the carboxyl group of one amino acid and the amino group of another), they form polypeptide chains.

●These chains subsequently fold into complex three-dimensional structures, which are essential for the functions of proteins.

Molecular Composition:

1. Amino acids are organic compounds characterized by a common structural framework comprising a central carbon atom (the alpha carbon), to which four distinct chemical groups are bonded.
2. These groups include an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (-H), and a variable side chain or R group.
3. It is the diversity of the R group that imparts unique properties to each amino acid, dictating its behavior and functionality within biological systems.

Backbone Configuration:

1. The backbone of an amino acid refers to the sequence of atoms extending from the alpha carbon to the carboxyl group and the amino group.
2. This backbone follows a linear arrangement, with the alpha carbon serving as the central anchor point.
3. The amino group is attached to the alpha carbon via a single covalent bond, while the carboxyl group is connected via a double bond, resulting in a distinct geometry that facilitates peptide bond formation and protein synthesis.

Stereochemistry:

1. Amino acids are chiral molecules, meaning they exist in two non-superimposable mirror-image forms known as enantiomers.
2. In nature, proteins predominantly consist of L-amino acids, where the amino group is positioned to the left of the central carbon when viewed in a Fischer projection.
3. This stereochemical specificity is crucial for the folding, structure, and function of proteins, as it determines the three-dimensional arrangement of amino acid residues within the polypeptide chain.

Amino Group:

1. The amino group (-NH2) of an amino acid is composed of a nitrogen atom bonded to two hydrogen atoms.
2. This group is responsible for conferring basicity to the amino acid molecule, allowing it to act as a proton acceptor in chemical reactions.
3. In the context of protein synthesis, the amino group serves as the site of attachment for subsequent amino acids during peptide bond formation, leading to the elongation of the polypeptide chain.

Carboxyl Group:

1. The carboxyl group (-COOH) of an amino acid consists of a carbon atom doubly bonded to an oxygen atom and singly bonded to a hydroxyl group (-OH).
2. This group imparts acidity to the amino acid molecule, rendering it capable of donating a proton in chemical reactions.
3. During protein synthesis, the carboxyl group of one amino acid undergoes condensation with the amino group of another amino acid, resulting in the formation of a peptide bond and the release of a water molecule.

Side Chain (R Group):

1. The side chain, also known as the R group, is the distinguishing feature of each amino acid, contributing to its unique chemical properties and functional roles.
2. The side chain can vary in size, structure, and chemical composition, encompassing a wide range of functionalities such as hydrophobicity, hydrophilicity, acidity, basicity, and reactivity.
3. The diversity of side chains among different amino acids is central to the diversity of protein structures and functions observed in biological systems.

Classification of Amino Acids According to Their Need:

20 amino acids are commonly found in proteins, and they can be categorized into two main groups: essential, non-essential and conditional amino acids.

Essential Amino Acids: Essential amino acids are building blocks of proteins that our bodies can’t produce on their own, so we must obtain them through diet. They’re crucial for various bodily functions and must be included in our meals to maintain health.

Conditional Amino Acids: Conditional amino acids are usually non-essential but become essential under certain conditions, such as illness or stress. During these times, our bodies may not produce enough of these amino acids, making dietary intake or supplementation necessary for optimal health.

Non-Essential Amino Acids: Non-essential amino acids are those our bodies can synthesize independently, meaning we don’t need to get them directly from food. Even though they’re not required in our diet, they still play vital roles in metabolism and overall health.

Classification of Amino Acids According to Their Interaction With Water:

The amino acids can be broadly categorized into two groups based on their interactions with water: hydrophilic and hydrophobic which also determines the relationship between protein structure and function.

Hydrophilic Amino Acids:

The hydrophilic amino acids possess functional groups that readily form hydrogen bonds and electrostatic interactions with water molecules. This behavior leads to enhanced solubility in aqueous solutions and a propensity to reside on the surface of proteins, where they interact with the surrounding water environment. Hydrophilic amino acids are crucial for mediating protein-protein interactions, ligand binding, and the stabilization of protein structures.

Polar Uncharged Amino Acids:

Serine (Ser), threonine (Thr), and asparagine (Asn) are characterized by polar side chains capable of hydrogen bonding with water. Their presence at protein surfaces facilitates interactions with solvent molecules and contributes to protein stability.

Positively Charged Amino Acids:

Arginine (Arg) and lysine (Lys) feature positively charged side chains that can engage in electrostatic interactions with negatively charged water molecules. These amino acids play a significant role in mediating protein-DNA interactions and enzyme catalysis.

Negatively Charged Amino Acids:

Aspartic acid (Asp) and glutamic acid (Glu) carry negatively charged side chains that interact favorably with positively charged water molecules. Their presence on protein surfaces facilitates interactions with other charged molecules and ions.

Hydrophobic Amino Acids:

Hydrophobic amino acids have nonpolar side chains that lack the ability to form hydrogen bonds with water. As a result, these amino acids tend to cluster together in the protein’s interior to minimize their exposure to water. The hydrophobic effect drives protein folding and stabilizes the protein’s three-dimensional structure.

Aliphatic Hydrophobic Amino Acids:

Alanine (Ala), valine (Val), leucine (Leu), isoleucine (Ile), and proline (Pro) are characterized by nonpolar side chains. These amino acids play a central role in the hydrophobic core of proteins, promoting stability and driving the folding process.

Aromatic Hydrophobic Amino Acids:

Phenylalanine (Phe) and tryptophan (Trp) possess aromatic rings that participate in hydrophobic interactions. These amino acids are often found buried within protein structures, contributing to the overall stability and structural integrity of proteins to prove the relationship between protein structure and function.

Classification of Amino Acids According to Their Charges :

In the relationship between protein structure and function, amino acids can be classified into three main categories based on their charges: acidic, basic, and neutral (also known as polar or nonpolar). The charge of an amino acid is determined by the presence of ionizable groups in its side chain (R group) which plays a crucial role in the relationship between protein structure and function.

Amino Acid	Charge	Property
Aspartic Acid (Asp, D)	Negative	Acidic
Glutamic Acid (Glu, E)	Negative	Acidic
Arginine (Arg, R)	Positive	Basic
Lysine (Lys, K)	Positive	Basic
Histidine (His, H)	Positive	Basic
Serine (Ser, S)	Neutral	Polar
Threonine (Thr, T)	Neutral	Polar
Tyrosine (Tyr, Y)	Neutral	Polar
Cysteine (Cys, C)	Neutral	Polar
Asparagine (Asn, N)	Neutral	Polar
Glutamine (Gln, Q)	Neutral	Polar
Alanine (Ala, A)	Neutral	Nonpolar
Valine (Val, V)	Neutral	Nonpolar
Leucine (Leu, L)	Neutral	Nonpolar
Isoleucine (Ile, I)	Neutral	Nonpolar
Methionine (Met, M)	Neutral	Nonpolar
Phenylalanine (Phe, F)	Neutral	Nonpolar
Tryptophan (Trp, W)	Neutral	Nonpolar
Proline (Pro, P)	Neutral	Nonpolar
Glycine (Gly, G)	Neutral	Nonpolar

Properties of Amino Acids:

The multifaceted properties of amino acids, shedding light on their significance in the cellular function and protein structure.

1. Properties of Amino Acids-Structural Diversity: Amino acids exhibit an astonishing structural diversity, stemming from the variability of their side chains. While the backbone of all amino acids remains consistent, it is the unique composition of the side chain, or R-group, that distinguishes one amino acid from another. This structural variability underlies the diverse chemical properties and functionalities observed across the amino acid spectrum.
2. Properties of Amino Acids-Acid-Base Behavior: One of the properties of amino acids is their ability to act as both acids and bases. This dual nature arises from the presence of an amino group (basic) and a carboxyl group (acidic) within their molecular structure. Depending on the pH of their environment, amino acids can either donate or accept protons, allowing them to participate in a wide range of chemical reactions critical for cellular function.
3. Properties of Amino Acids-Ionization States: Amino acids exist in different ionization states depending on the prevailing pH conditions. At physiological pH, most amino acids adopt a zwitterionic form, where the amino group is protonated (+NH3) and the carboxyl group is deprotonated (-COO-). This balanced charge distribution confers stability to proteins and influences their interactions with other molecules in the cellular milieu.
4. Properties of Amino Acids-Hydrophobicity and Hydrophilicity: The hydrophobic or hydrophilic nature of amino acids is largely determined by the characteristics of their side chains. Hydrophobic amino acids possess nonpolar side chains that tend to cluster together in the interior of proteins, away from the surrounding aqueous environment. In contrast, hydrophilic amino acids feature polar or charged side chains that interact favorably with water molecules, often residing on the protein surface.
5. Properties of Amino Acids-Stereochemistry: According to the properties of amino acids, they are chiral molecules, meaning they exist in two mirror-image forms known as enantiomers. In nature, proteins predominantly consist of L-amino acids, with a specific spatial arrangement of atoms around the central carbon atom. This stereochemical specificity is crucial for protein folding and function, as it dictates the three-dimensional structure and interactions of the resulting polypeptide chains.
6. Properties of Amino Acids-Chemical Reactivity: Among the properties of amino acids, they exhibit diverse chemical reactivity, serving as substrates for various enzymatic reactions and post-translational modifications. Functional groups within the side chains of amino acids can undergo transformations such as phosphorylation, acetylation, or glycosylation, modulating the activity, stability, and localization of proteins within the cell. These chemical modifications expand the functional repertoire of proteins, allowing for precise regulation of cellular processes.
7. Properties of Amino Acids-Role in Protein Structure: The properties of amino acids play a pivotal role in determining the structure and function of proteins. The sequence and spatial arrangement of amino acid residues dictate the folding pattern and stability of the protein, ultimately defining its biological activity and specificity. Interactions between amino acids, such as hydrogen bonding and hydrophobic interactions, contribute to the intricate architecture of proteins and their ability to perform specialized functions.

Click here to learn how the properties of amino acids determine the Relationship Between Protein Structure and Function.

General Functions of Amino Acids:

1. Metabolism: Amino acids participate in metabolic pathways, serving as precursors for the synthesis of other important molecules like hormones, neurotransmitters, and nucleotides.
2. Enzyme Function: Amino acids can act as coenzymes or cofactors, assisting enzymes in catalyzing biochemical reactions.
3. Cell Signaling: Some amino acids function as signaling molecules in cell communication processes.
4. Energy Source: In times of need, amino acids can be broken down and used for energy production.
5. Structural Components: Amino acids are components of non-protein structures, such as collagen (a structural protein in connective tissues) and elastin.

Specific Functions of Amino Acids:

Depending on the properties of amino acids, the table below provides a comprehensive overview of the diverse functions of amino acids in various physiological processes, highlighting their importance in cellular metabolism, neurotransmission, immune function, and structural integrity.

Proteins are the molecular architects of life and the properties of amino acids determine the structure and function of the proteins.

Amino Acid	Function
Alanine	Precursor for glucose production during fasting, plays a role in energy metabolism
Arginine	Precursor for nitric oxide synthesis, involved in immune function, wound healing, and hormone secretion
Asparagine	Involved in protein synthesis, serves as a precursor for the synthesis of other amino acids
Aspartic Acid	Acts as a neurotransmitter in the central nervous system, involved in energy metabolism
Cysteine	Important for the formation of disulfide bonds in proteins, serves as an antioxidant
Glutamine	Essential for immune function, serves as a precursor for nucleotide synthesis
Glutamic Acid	Acts as a neurotransmitter, involved in energy metabolism and protein synthesis
Glycine	Important for the synthesis of heme, collagen, and glutathione, serves as an inhibitory neurotransmitter in the central nervous system
Histidine	Precursor for histamine synthesis, involved in acid-base balance and neurotransmission
Isoleucine	Essential for protein synthesis, serves as a precursor for acetyl-CoA
Leucine	Stimulates protein synthesis, regulates blood sugar levels, serves as an energy source
Lysine	Essential for protein synthesis, important for collagen formation and calcium absorption
Methionine	Essential for protein synthesis, serves as a precursor for other sulfur-containing compounds
Phenylalanine	Precursor for the synthesis of tyrosine and neurotransmitters such as dopamine and norepinephrine
Proline	Important for the structure of collagen and connective tissues, serves as a precursor for the synthesis of other amino acids
Serine	Involved in protein synthesis and the synthesis of neurotransmitters, important for cell membrane structure
Threonine	Essential for protein synthesis, important for antibody production and immune function
Tryptophan	Precursor for serotonin synthesis, involved in mood regulation and sleep
Tyrosine	Precursor for the synthesis of neurotransmitters such as dopamine, norepinephrine, and epinephrine, important for thyroid hormone synthesis
Valine	Essential for protein synthesis, serves as a precursor for glucose production during fasting

Sources and Deficiencies of Each Amino Acids:

Depending on the properties of amino acids, the table below provides a comprehensive overview of the dietary sources of individual amino acids and the potential symptoms of deficiency associated with inadequate intake. Maintaining a balanced diet rich in protein-containing foods is essential for meeting the body’s requirements for amino acids and supporting overall health and well-being.

Amino Acid	Dietary Sources	Deficiency Symptoms
Alanine	Meat, poultry, fish, dairy, nuts, seeds, legumes	Muscle weakness, fatigue, decreased immunity
Arginine	Meat, poultry, dairy, seafood, nuts, seeds, legumes	Poor wound healing, immune dysfunction, infertility
Asparagine	Asparagus, potatoes, legumes, nuts, seeds, whole grains	Impaired cognitive function, fatigue, decreased immune response
Aspartic Acid	Meat, poultry, fish, dairy, eggs, legumes	Fatigue, depression, impaired memory and cognition
Cysteine	Meat, poultry, fish, dairy, eggs, soybeans, broccoli, Brussels sprouts	Hair loss, skin disorders, compromised immune function
Glutamine	Beef, chicken, fish, dairy, eggs, cabbage, spinach	Impaired immune function, muscle wasting, digestive issues
Glutamic Acid	Soy sauce, tomatoes, cheese, mushrooms, peas, walnuts	Fatigue, poor concentration, headaches
Glycine	Meat, poultry, fish, dairy, beans, spinach, kale, cabbage	Poor wound healing, muscle loss, neurological symptoms
Histidine	Meat, poultry, fish, dairy, eggs, grains, legumes	Anemia, growth impairment, neurological disorders
Isoleucine	Meat, poultry, fish, dairy, eggs, soybeans, lentils, nuts	Fatigue, muscle weakness, impaired wound healing
Leucine	Meat, poultry, fish, dairy, eggs, soybeans, peanuts, almonds	Fatigue, muscle loss, decreased appetite
Lysine	Meat, poultry, fish, dairy, eggs, beans, quinoa, nuts	Fatigue, anemia, impaired growth and development
Methionine	Meat, poultry, fish, dairy, eggs, Brazil nuts, sesame seeds	Fatigue, muscle weakness, poor skin and hair health
Phenylalanine	Meat, poultry, fish, dairy, eggs, soybeans, almonds, peanuts	Cognitive impairment, mood disorders, skin conditions
Proline	Meat, poultry, fish, dairy, eggs, soybeans, wheat germ, cabbage	Joint pain, muscle weakness, skin disorders
Serine	Meat, poultry, fish, dairy, eggs, legumes, nuts, seeds	Fatigue, poor digestion, impaired immune function
Threonine	Meat, poultry, fish, dairy, eggs, legumes, nuts, seeds	Digestive issues, skin disorders, compromised immune function
Tryptophan	Meat, poultry, fish, dairy, eggs, soybeans, pumpkin seeds, oats	Mood disorders, insomnia, decreased immunity
Tyrosine	Meat, poultry, fish, dairy, eggs, soybeans, almonds, pumpkin seeds	Fatigue, depression, impaired cognitive function
Valine	Meat, poultry, fish, dairy, eggs, soybeans, lentils, peanuts	Muscle weakness, poor coordination, decreased immunity

The properties of amino acids not only unveils the intricacies of protein structure and function but also underscores their significance in maintaining cellular homeostasis and orchestrating the symphony of biological processes.

Frequently Asked Questions(FAQ):

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

Classes of Vertebrata

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.

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