About this NEET Biology practice test

The gap between a good NEET score and a great one is almost always Biology, since it's worth as many marks as Physics and Chemistry put together. What makes it scoreable is also what makes it unforgiving: NEET tests the exact NCERT line, not a paraphrase, so knowing that residual volume is close to 1200 mL or that a biodiversity hotspot needs 1500 endemic plant species is the difference between a right and a wrong answer. This set is built the way NCERT actually reads — precise numbers, exact terminology, one clean fact per question — spanning Cell Biology, Genetics, Physiology, Reproduction, Evolution, Biotechnology and Ecology. Work through it the way you'd revise the textbook itself, line by line.

NEET Biology Practice Test sample questions

These starter questions help you launch a biology mock test quickly. Swap them with your own worksheet, notebook, or textbook questions any time.

1. 1. Which taxonomic category represents a group of related families sharing a few similar characters that set them apart from other such groups, as seen in the order Carnivora which includes the families Felidae and Canidae?

2. 2. Lichens, which are widely used as pollution indicators because they fail to grow in polluted areas, represent a symbiotic association between which two groups of organisms?

3. 3. Which group of plants is referred to as the 'amphibians of the plant kingdom' because, although they can grow on soil, water is still required for the sexual/fertilization process?

4. 4. Which animal phylum is characterized by a unique water-vascular system used in locomotion, and shows an exclusively deuterostome pattern of embryonic development?

5. 5. Which cell organelle, discovered by Camillo Golgi, packages and modifies proteins and lipids received from the endoplasmic reticulum and is also responsible for forming the cell plate during cytokinesis in plant cells?

6. 6. During which phase of the cell cycle does DNA replication occur, resulting in each chromosome consisting of two identical sister chromatids joined at the centromere?

7. 7. In C4 plants such as maize, the first stable product of CO2 fixation in mesophyll cells is a four-carbon compound. Name this compound and the enzyme that catalyzes its formation from phosphoenolpyruvate.

8. 8. A respiratory quotient (RQ) value of 1 during aerobic respiration indicates that which type of substrate is being used?

9. 9. In angiosperms, entry of the pollen tube into the ovule through the micropyle is called porogamy. What is the term for entry through the chalaza instead?

10. 10. In the human male reproductive system, which cells located within the seminiferous tubules nourish the developing germ cells and secrete the hormone inhibin?

11. 11. Which enzyme, secreted by gastric glands as inactive pepsinogen and activated by hydrochloric acid, converts dietary proteins into proteoses and peptones in the stomach?

12. 12. What is the approximate residual volume of the human lungs, that is, the volume of air remaining in the lungs even after the most forcible expiration?

13. 13. Which part of the nephron is chiefly responsible for reabsorbing nearly 70-80% of the glomerular filtrate, including glucose, amino acids, and a major fraction of electrolytes and water?

14. 14. Of the 12 pairs of ribs in the human thoracic cage, how many pairs are classified as 'floating ribs' because they do not attach to the sternum either directly or through cartilage?

15. 15. Which valve of the human heart, situated between the left atrium and left ventricle, prevents the backflow of blood into the atrium during ventricular systole?

16. 16. What is the term for the minute gap between two adjacent neurons across which a nerve impulse is transmitted with the help of neurotransmitters?

17. 17. In a dihybrid cross between two pea plants heterozygous for seed shape and seed colour (RrYy x RrYy), what phenotypic ratio is expected in the F2 generation according to Mendel's law of independent assortment?

18. 18. The human ABO blood group system shows a type of gene interaction in which both the IA and IB alleles express themselves fully and simultaneously in a heterozygote, producing blood group AB. What is this phenomenon called?

19. 19. In Mirabilis jalapa, a cross between a red-flowered plant (RR) and a white-flowered plant (rr) produces pink-flowered offspring (Rr) in the F1 generation. What term describes this pattern, where the heterozygote phenotype is intermediate between both parents?

20. 20. According to the Hardy-Weinberg principle, if the frequency of a recessive allele 'q' in a population at genetic equilibrium is 0.2, what is the expected frequency of homozygous dominant individuals (p^2) in that population?

21. 21. Which evolutionary process describes how a single ancestral species gives rise to several different species that occupy different habitats or niches, as exemplified by Darwin's finches on the Galapagos Islands?

22. 22. Which bacterium is the source of the antibiotic streptomycin?

23. 23. In human malaria, the female Anopheles mosquito transmits a protozoan parasite of which genus, and which stage of this parasite, present in the mosquito's salivary glands, is infective to humans?

24. 24. Which restriction endonuclease, isolated from Escherichia coli and commonly used in recombinant DNA technology, recognizes the palindromic sequence GAATTC?

25. 25. In agarose gel electrophoresis used to separate DNA fragments, which fluorescent dye is used to visualize the DNA bands under UV light, and towards which electrode do the DNA fragments migrate?

26. 26. In which type of ecosystem is the pyramid of biomass typically inverted, with the standing biomass of producers (phytoplankton) being smaller than that of the primary consumers (zooplankton) at any given moment?

27. 27. In Raunkiaer's classification of plant life-forms, which category is defined by perennating buds located at the soil surface, where they are protected by the soil and surrounding leaf litter?

28. 28. The phosphorus cycle is classified as a sedimentary biogeochemical cycle. What is the main reservoir of phosphorus that gives this cycle its sedimentary character?

29. 29. Which international agreement, adopted in 1987, aims to protect the stratospheric ozone layer by phasing out the production of ozone-depleting substances such as CFCs?

30. 30. As per the biodiversity hotspot criteria proposed by Norman Myers, a region must contain at least how many endemic vascular plant species, in addition to having lost 70% or more of its original habitat, to qualify as a hotspot?

Answer key & quick explanations

Short answers for the sample questions above. Use this to self-check before generating a fresh AI-built mock test.

1. 1. Which taxonomic category represents a group of related families sharing a few similar characters that set them apart from other such groups, as seen in the order Carnivora which includes the families Felidae and Canidae?

   Order

   The taxonomic hierarchy runs Species-Genus-Family-Order-Class-Phylum-Kingdom, with each rank grouping together the more closely related units below it. An order clusters several similar families, exactly as Carnivora brings together Felidae (cats) and Canidae (dogs) on the basis of shared carnivorous adaptations. This is one level broader than a family, which itself groups related genera.

2. 2. Lichens, which are widely used as pollution indicators because they fail to grow in polluted areas, represent a symbiotic association between which two groups of organisms?

   Algae (phycobiont) and fungi (mycobiont)

   In a lichen, the algal partner is photosynthetic and prepares food for the fungus, while the fungal partner provides shelter, absorbs water and minerals, and protects the alga. This mutualistic partnership is extremely sensitive to sulphur dioxide and other atmospheric pollutants, which is precisely why lichens vanish from industrially polluted areas and serve as bioindicators.

3. 3. Which group of plants is referred to as the 'amphibians of the plant kingdom' because, although they can grow on soil, water is still required for the sexual/fertilization process?

   Bryophytes

   Bryophytes, such as mosses and liverworts, lack true vascular tissue and true roots, so their gametes (particularly the motile male gametes) must swim through a film of surface water to reach the egg. This dependence on external water for fertilization despite an otherwise terrestrial existence is the basis for the amphibian analogy.

4. 4. Which animal phylum is characterized by a unique water-vascular system used in locomotion, and shows an exclusively deuterostome pattern of embryonic development?

   Echinodermata

   Echinoderms such as starfish and sea urchins possess a distinctive water-vascular system with tube feet that function in locomotion, capture of food, and respiration. Unlike most other invertebrate phyla, which are protostomes, echinoderms share the deuterostome developmental pattern (blastopore becomes the anus) with chordates, hinting at their closer evolutionary relationship to vertebrates.

5. 5. Which cell organelle, discovered by Camillo Golgi, packages and modifies proteins and lipids received from the endoplasmic reticulum and is also responsible for forming the cell plate during cytokinesis in plant cells?

   Golgi apparatus (Golgi complex/body)

   The Golgi apparatus consists of flattened, disc-shaped cisternae that receive vesicles budded off from the endoplasmic reticulum, chemically modify their contents (such as by glycosylation), and package the finished products into vesicles for secretion or delivery elsewhere. In dividing plant cells, Golgi-derived vesicles fuse at the equatorial plane to build the cell plate that becomes the new cell wall separating daughter cells.

6. 6. During which phase of the cell cycle does DNA replication occur, resulting in each chromosome consisting of two identical sister chromatids joined at the centromere?

   S (Synthesis) phase of interphase

   Interphase is divided into G1, S, and G2 phases, and it is specifically during the S phase that the cell duplicates its entire genome. Because replication produces two identical copies of each chromosome held together at the centromere, a cell entering mitosis after S phase has chromosomes made of two sister chromatids rather than one.

7. 7. In C4 plants such as maize, the first stable product of CO2 fixation in mesophyll cells is a four-carbon compound. Name this compound and the enzyme that catalyzes its formation from phosphoenolpyruvate.

   Oxaloacetic acid (OAA), formed by the enzyme PEP carboxylase (PEPcase)

   In the Hatch-Slack (C4) pathway, atmospheric CO2 is first fixed in the mesophyll cells by combining with the three-carbon acceptor phosphoenolpyruvate under the action of PEP carboxylase, which has a very high affinity for CO2 and no oxygenase activity. This reaction yields the four-carbon oxaloacetic acid, which is subsequently converted to malate or aspartate and shuttled to the bundle sheath cells for decarboxylation and entry into the Calvin cycle.

8. 8. A respiratory quotient (RQ) value of 1 during aerobic respiration indicates that which type of substrate is being used?

   Carbohydrates

   RQ is the ratio of the volume of CO2 evolved to the volume of O2 consumed during respiration. When carbohydrates are fully oxidized, equal volumes of CO2 are released for every volume of O2 consumed, giving an RQ of exactly 1, whereas fats give an RQ below 1 and certain organic acids give an RQ above 1.

9. 9. In angiosperms, entry of the pollen tube into the ovule through the micropyle is called porogamy. What is the term for entry through the chalaza instead?

   Chalazogamy

   Most angiosperms show porogamy, where the pollen tube grows straight through the micropylar opening to reach the embryo sac, but in a few plants such as Casuarina the tube instead enters through the chalazal end of the ovule, a route termed chalazogamy. A third, rarer route through the integuments rather than the micropyle or chalaza is called mesogamy.

10. 10. In the human male reproductive system, which cells located within the seminiferous tubules nourish the developing germ cells and secrete the hormone inhibin?

    Sertoli cells

    Sertoli cells, also called nurse cells, are found in the germinal epithelium of the seminiferous tubules and provide nutrients to the dividing and differentiating spermatogenic cells. They also secrete inhibin, which exerts negative feedback control on FSH secretion from the anterior pituitary, helping regulate the rate of spermatogenesis.

11. 11. Which enzyme, secreted by gastric glands as inactive pepsinogen and activated by hydrochloric acid, converts dietary proteins into proteoses and peptones in the stomach?

    Pepsin

    Gastric chief (peptic) cells secrete pepsinogen, an inactive zymogen that would digest the cell's own proteins if released in active form. Hydrochloric acid from oxyntic cells converts pepsinogen into active pepsin, which then breaks down proteins into smaller proteoses and peptones, setting up the substrate for further digestion in the small intestine.

12. 12. What is the approximate residual volume of the human lungs, that is, the volume of air remaining in the lungs even after the most forcible expiration?

    Approximately 1200 mL

    Even after the most forceful possible expiration, the alveoli and airways cannot be completely emptied, and around 1200 mL of air remains trapped in the lungs; this is the residual volume. Its presence keeps the alveoli slightly inflated between breaths and allows some gas exchange to continue even during expiration.

13. 13. Which part of the nephron is chiefly responsible for reabsorbing nearly 70-80% of the glomerular filtrate, including glucose, amino acids, and a major fraction of electrolytes and water?

    Proximal convoluted tubule (PCT)

    The PCT is lined with cells bearing extensive microvilli that vastly increase the absorptive surface area, allowing it to reclaim the bulk of the filtered glucose, amino acids, and a large share of sodium, chloride, and water back into the peritubular capillaries. Only the remaining, more concentrated filtrate passes on to the loop of Henle for further processing.

14. 14. Of the 12 pairs of ribs in the human thoracic cage, how many pairs are classified as 'floating ribs' because they do not attach to the sternum either directly or through cartilage?

    2 pairs (the 11th and 12th pairs)

    Of the twelve pairs of ribs, the first seven are true ribs attaching directly to the sternum by their own costal cartilage, the next three (8th-10th) are false ribs attaching indirectly via the cartilage of the rib above, and the last two pairs have no sternal attachment at all, leaving their anterior ends free and earning them the name floating ribs.

15. 15. Which valve of the human heart, situated between the left atrium and left ventricle, prevents the backflow of blood into the atrium during ventricular systole?

    Bicuspid (mitral) valve

    The bicuspid valve, so named because it has two flaps or cusps, guards the atrioventricular opening on the left side of the heart. When the left ventricle contracts during systole, the rising pressure forces this valve shut, ensuring blood is pumped forward into the aorta rather than regurgitating back into the left atrium.

16. 16. What is the term for the minute gap between two adjacent neurons across which a nerve impulse is transmitted with the help of neurotransmitters?

    Synapse

    At a chemical synapse, the arrival of an electrical impulse at the axon terminal triggers the release of neurotransmitter molecules stored in synaptic vesicles into the narrow synaptic cleft. These neurotransmitters diffuse across the gap and bind to receptors on the postsynaptic neuron's membrane, generating a new impulse and allowing the signal to continue onward.

17. 17. In a dihybrid cross between two pea plants heterozygous for seed shape and seed colour (RrYy x RrYy), what phenotypic ratio is expected in the F2 generation according to Mendel's law of independent assortment?

    9:3:3:1

    Because the two gene pairs assort independently during gamete formation, each RrYy parent produces four types of gametes (RY, Ry, rY, ry) in equal proportion, and their random combination in a Punnett square yields nine round-yellow, three round-green, three wrinkled-yellow, and one wrinkled-green offspring. This 9:3:3:1 ratio was the key evidence Mendel used to formulate independent assortment.

18. 18. The human ABO blood group system shows a type of gene interaction in which both the IA and IB alleles express themselves fully and simultaneously in a heterozygote, producing blood group AB. What is this phenomenon called?

    Codominance

    In codominance, neither allele masks the other; instead both are expressed together and independently in the phenotype. In an IAIB individual, the red blood cells display both A and B surface antigens simultaneously rather than a blended or intermediate antigen, distinguishing codominance from incomplete dominance.

19. 19. In Mirabilis jalapa, a cross between a red-flowered plant (RR) and a white-flowered plant (rr) produces pink-flowered offspring (Rr) in the F1 generation. What term describes this pattern, where the heterozygote phenotype is intermediate between both parents?

    Incomplete dominance

    Unlike classical Mendelian dominance where one allele completely masks the other, incomplete dominance occurs when neither allele is fully dominant, so the heterozygote shows a blended phenotype partway between the two parents. In Mirabilis jalapa, the single functional copy of the pigment-producing allele in the Rr plant produces only enough pigment for a pink, rather than fully red, flower.

20. 20. According to the Hardy-Weinberg principle, if the frequency of a recessive allele 'q' in a population at genetic equilibrium is 0.2, what is the expected frequency of homozygous dominant individuals (p^2) in that population?

    0.64

    The Hardy-Weinberg equation states that p + q = 1 and p^2 + 2pq + q^2 = 1, where p^2, 2pq, and q^2 represent the frequencies of the homozygous dominant, heterozygous, and homozygous recessive genotypes respectively. Given q = 0.2, p works out to 0.8, so the homozygous dominant frequency p^2 equals 0.8 squared, which is 0.64.

21. 21. Which evolutionary process describes how a single ancestral species gives rise to several different species that occupy different habitats or niches, as exemplified by Darwin's finches on the Galapagos Islands?

    Adaptive radiation

    Adaptive radiation occurs when a single ancestral lineage diversifies rapidly into many descendant species, each becoming specialized for a distinct ecological niche within a relatively confined geographic area. Darwin observed exactly this among the Galapagos finches, where beak shapes and sizes diverged from a common ancestor to suit different available food sources such as seeds, insects, and cactus flowers.

22. 22. Which bacterium is the source of the antibiotic streptomycin?

    Streptomyces griseus

    Streptomycin was isolated from the soil actinomycete Streptomyces griseus and was historically important as one of the first antibiotics effective against tuberculosis. Along with other Streptomyces species that yield antibiotics such as chloramphenicol and tetracycline, it illustrates how soil microbes are exploited in human welfare through antibiotic production.

23. 23. In human malaria, the female Anopheles mosquito transmits a protozoan parasite of which genus, and which stage of this parasite, present in the mosquito's salivary glands, is infective to humans?

    Plasmodium; the sporozoite stage is infective to humans

    Malaria is caused by protozoan parasites of the genus Plasmodium, several species of which infect humans, including P. vivax and P. falciparum. Following sexual reproduction and development inside the mosquito's gut wall, sporozoites migrate to the salivary glands and are injected into the human bloodstream when the infected female Anopheles takes a blood meal, initiating the liver stage of infection.

24. 24. Which restriction endonuclease, isolated from Escherichia coli and commonly used in recombinant DNA technology, recognizes the palindromic sequence GAATTC?

    EcoRI

    EcoRI is one of the earliest and most widely used restriction enzymes, obtained from a strain of Escherichia coli, and it cleaves double-stranded DNA specifically at the palindromic sequence GAATTC. The cut is made between the G and the adjacent A on each strand, generating short single-stranded overhangs known as sticky ends that facilitate the joining of foreign DNA into a vector.

25. 25. In agarose gel electrophoresis used to separate DNA fragments, which fluorescent dye is used to visualize the DNA bands under UV light, and towards which electrode do the DNA fragments migrate?

    Ethidium bromide; the fragments migrate towards the anode (positive electrode)

    DNA fragments carry a net negative charge because of their phosphate backbone, so when an electric field is applied across the agarose gel, they migrate towards the positively charged anode, with smaller fragments moving faster through the gel matrix than larger ones. Since DNA itself is colourless, the gel is stained with ethidium bromide, which intercalates between the bases and fluoresces orange under UV illumination, revealing the separated bands.

26. 26. In which type of ecosystem is the pyramid of biomass typically inverted, with the standing biomass of producers (phytoplankton) being smaller than that of the primary consumers (zooplankton) at any given moment?

    A marine/sea ecosystem

    In the sea, producers such as phytoplankton are tiny, short-lived, and reproduce extremely rapidly, so their standing crop biomass at any single instant is small even though their overall rate of production is high. Because zooplankton graze on them continuously while living longer, the biomass of these primary consumers can exceed that of the producers, giving an inverted pyramid of biomass despite energy still flowing normally from producers upward.

27. 27. In Raunkiaer's classification of plant life-forms, which category is defined by perennating buds located at the soil surface, where they are protected by the soil and surrounding leaf litter?

    Hemicryptophytes

    Raunkiaer classified plants based on the position of their perennating buds relative to the soil surface as a way of showing how plants survive unfavourable seasons. Hemicryptophytes keep their buds right at ground level, sheltered by a covering of soil, dead leaves, or snow, which distinguishes them from phanerophytes with buds held well above the ground and cryptophytes with buds buried below the surface.

28. 28. The phosphorus cycle is classified as a sedimentary biogeochemical cycle. What is the main reservoir of phosphorus that gives this cycle its sedimentary character?

    Earth's crust (rocks and sediments)

    Unlike gaseous cycles such as those of carbon and nitrogen, which have the atmosphere as their principal reservoir, phosphorus has no significant gaseous phase and is instead locked away mainly in rocks and sedimentary deposits of the Earth's crust. Weathering of these rocks slowly releases phosphate into soil and water, from where it enters living organisms through plant uptake, making the cycle characteristically slow and sediment-based.

29. 29. Which international agreement, adopted in 1987, aims to protect the stratospheric ozone layer by phasing out the production of ozone-depleting substances such as CFCs?

    The Montreal Protocol

    The Montreal Protocol on Substances that Deplete the Ozone Layer was signed in 1987 in response to growing evidence, including the discovery of the Antarctic ozone hole, that chlorofluorocarbons and related compounds were destroying stratospheric ozone. Signatory nations committed to phasing out production and use of these chemicals, and the protocol is widely regarded as one of the most successful international environmental agreements.

30. 30. As per the biodiversity hotspot criteria proposed by Norman Myers, a region must contain at least how many endemic vascular plant species, in addition to having lost 70% or more of its original habitat, to qualify as a hotspot?

    1500 endemic vascular plant species

    Myers defined biodiversity hotspots using two quantitative criteria: the region must harbour at least 1500 species of vascular plants found nowhere else (endemics), and it must have already lost 70% or more of its original natural habitat to human activity. India's Western Ghats-Sri Lanka and Indo-Burma regions are among the global hotspots identified using these thresholds.

Curriculum Mapping & Learning Guide

Use this breakdown to identify which skills each question tests and guide post-test review.

NEET Biology units covered

1. Chapter 1: The Living World and Biological Classification
2. Chapter 2: Plant Kingdom and Animal Kingdom
3. Chapter 3: Cell – The Unit of Life and Cell Cycle
4. Chapter 4: Plant Physiology (Photosynthesis, Respiration, Transport)
5. Chapter 5: Human Physiology (Digestion, Breathing, Excretion, Locomotion)
6. Chapter 6: Reproduction in Organisms (Plants and Humans)
7. Chapter 7: Genetics and Evolution
8. Chapter 8: Biology in Human Welfare (Health, Microbes, Food)
9. Chapter 9: Biotechnology and Its Applications
10. Chapter 10: Ecology and Environment (Ecosystem, Biodiversity, Pollution)

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