Quantrex Academy Quantrex AcademyPYQs with solutions · JEE · NEET · NDA

Home · NEET UG · Biology · Chapter

Chapter — NEET UG Biology PYQs

733 previous year questions from Chapter with answers and solutions. Numbered list, year tags, and one-tap solutions — built for serious JEE / NEET practice.

733 questionsBiologySolutions on every page
1

Consider the following three biomolecules: X: Uridine Y: Cytidylic acid Z: Guanine Choose the option that correctly categorizes X, Y, and Z.

NEET 2026 Solution View → 2

The complete, catalytically active enzyme together with its bound non-protein constituent is known as:

NEET 2026 Solution View → 3

During a laboratory experiment, a student accidentally boils a sample of salivary amylase before adding it to a starch solution. Which of the following best explains the most likel

NEET 2026 Solution View → 4

During a biological survey, a researcher discovers a new organism. To classify it properly, she examines its external and internal structure, cellular organization, developmental p

NEET 2026 Solution View → 5

Given below are the stages in the sexual reproduction of higher fungi. Arrange the following stages in the correct sequence. A. Fusion of parental nuclei (Karyogamy) B. Meiosis in

NEET 2026 Solution View → 6

Read the given statements regarding the general characteristics of bryophytes and select the incorrect statement.

NEET 2026 Solution View → 7

Arrange the following male reproductive structures of gymnosperms in descending order of their physical hierarchy (macroscopic to microscopic). A. Microsporangium B. Microspore C.

NEET 2026 Solution View → 8

Which of the following sets of plants is correctly paired with the nature of its dominant plant body and the status of its vascular tissues?

NEET 2026 Solution View → 9

Members of class Chondrichthyes have to swim constantly to avoid sinking. This is primarily due to the:

NEET 2026 Solution View → 10

In a typical dicotyledonous seed, the distinct scar on the seed coat through which the developing seed was attached to the fruit is referred to as the:

NEET 2026 Solution View → 11

In which of the following plants can the flower be divided into two equal radial halves in any radial plane passing through the centre?

NEET 2026 Solution View → 12

Which of the following anatomical features is characteristic of the vascular bundles in a monocotyledonous stem?

NEET 2026 Solution View → 13

The small disc-shaped structures at the surface of the centromeres, which serve as the sites of attachment for spindle fibres during karyokinesis, are known as:

NEET 2026 Solution View → 14

In a bacterial cell, the plasma membrane often extends into the cytoplasm to form a specialised structure. These membranous extensions are typically found in the form of:

NEET 2026 Solution View → 15

Internode elongation just prior to flowering in plants with a rosette habit, such as cabbage and beet, is specifically promoted by the application of:

NEET 2026 Solution View → 16

During the electron transport system (ETS) in mitochondria, which of the following enzyme complexes contains cytochromes a and a₃ along with two copper centres?

NEET 2026 Solution View → 17

Carboxylation is considered the most crucial step of the Calvin cycle. Which of the following events specifically characterizes this stage?

NEET 2026 Solution View → 18

A botanist is studying microsporogenesis and microgametogenesis in an angiosperm species that sheds its pollen at the 3-celled stage. To generate exactly 100 such mature pollen gra

NEET 2026 Solution View → 19

In recent years, conservation strategies for threatened species have advanced significantly. Which of the following is considered an advanced method of ex-situ conservation?

NEET 2026 Solution View → 20

The 'Evil Quartet' describes the four major causes of biodiversity loss. Which of the following examples is incorrectly matched with its corresponding cause?

NEET 2026 Solution View → 21

Most ecosystems on Earth rely on a continuous and strictly unidirectional flow of solar energy. Which of the following statements correctly explains the necessity of this continuou

NEET 2026 Solution View → 22

In Rana tigrina , which of the following external morphological features is exclusively present in males and helps in distinguishing them from females?

NEET 2026 Solution View → 23

In the anatomy of a frog's heart, the single ventricle opens into a specialized sac-like structure located on the ventral side. Identify this structure from the given options.

NEET 2026 Solution View → 24

During a "fight or flight" response, the adrenal medulla rapidly releases catecholamines into the bloodstream. Which of the following sets of physiological and metabolic changes is

NEET 2026 Solution View → 25

Given below is a schematic representation of a mammalian nephron with certain parts labeled as A, B, C, and D. Select the correct statement regarding the physiological functions of

NEET 2026 Solution View → 26

Mechanisms of breathing vary among different groups of animals depending mainly on their habitats and levels of organisation. Identify the incorrect match between the animal group

NEET 2026 Solution View → 27

In the human menstrual cycle, the remaining parts of the Graafian follicle transform into the corpus luteum during the :

NEET 2026 Solution View → 28

A couple is expecting monozygotic twins. Which of the following correctly represents the number of ova and sperms that participated in the fertilization process to form these twins

NEET 2026 Solution View → 29

According to the accepted principles of molecular biology, which of the following criteria must be fulfilled by a molecule to act as a suitable genetic material? (a) It should be a

NEET 2026 Solution View → 30

One of the major observations derived from the Human Genome Project was regarding the proportion of DNA that actually translates into functional products. According to the salient

NEET 2026 Solution View → 31

The basic nature of histone proteins allows them to tightly pack the DNA helix. This property is due to the presence of positive charges on which specific part of their constituent

NEET 2026 Solution View → 32

In a bacterial cell, if the (sigma) factor becomes non-functional, which specific event during transcription will be directly prevented?

NEET 2026 Solution View → 33

In a Mendelian dihybrid cross, a true-breeding pea plant with inflated green pods is crossed with a true-breeding plant having constricted yellow pods. The F₁ offspring are then se

NEET 2026 Solution View → 34

Study the given pedigree chart showing the inheritance of a genetic disorder in a family. What is the probability that the first child (III-1) born to the couple II-2 and II-3 will

NEET 2026 Solution View → 35

Which of the following features accurately describes a typical antibody molecule?

NEET 2026 Solution View → 36

Observe the given list of lymphoid organs and tissues: Spleen, Thymus, Tonsils, Bone marrow, Peyer's patches, Appendix How many of these structures provide the micro-environments f

NEET 2026 Solution View → 37

A human child is born with certain non-specific defense mechanisms that prevent the entry of pathogens. Which of the following represents a physical barrier of this innate immune s

NEET 2026 Solution View → 38

Which of the following microbes are commercially exploited for the production of enzymes and bioactive molecules used specifically in medical therapies? A. Streptococcus B. Clostri

NEET 2026 Solution View → 39

During the artificial synthesis of human insulin by Eli Lilly, the A and B chains were produced separately and extracted. Which type of linkage was artificially created between the

NEET 2026 Solution View → 40

In the development of transgenic tobacco plants resistant to the nematode Meloidogyne incognita , Agrobacterium vectors are used to introduce nematode-specific genes into the host.

NEET 2026 Solution View → 41

During the amplification of a gene of interest using PCR, a researcher sets the thermocycler for 5 continuous cycles. Assuming perfect efficiency, how many copies of the target DNA

NEET 2026 Solution View → 42

Observe the schematic representation of the cloning vector pBR322 given below. If a foreign DNA fragment is successfully ligated at the PvuI restriction site, which of the followin

NEET 2026 Solution View → 43

Observe the given diagram of a specific type of bioreactor. Identify the correct statement regarding the component/feature labeled 'A'.

NEET 2026 Solution View → 44

A clown fish lives among the stinging tentacles of a sea anemone and gets protection from predators, while the anemone does not appear to derive any benefit nor is it harmed. This

NEET 2026 Solution View → 45

According to the principles of biological organisation, ecology at the organismic level is essentially:

NEET 2026 Solution View → 46

In a habitat with limited resources, a population exhibits Verhulst-Pearl logistic growth. The growth curve reaches an asymptote when:

NEET 2026 Solution View → 47

The division of Kingdom Fungi into various classes (such as Phycomycetes, Ascomycetes, etc.) is primarily based on which of the following sets of features?

NEET 2026 Solution View → 48

Observe the given figure illustrating a specific arrangement of floral parts on the thalamus. Identify the type of flower, the relative position of the ovary, and a correct example

NEET 2026 Solution View → 49

At which stage of mitosis do the chromosomes reach their respective poles, decondense, and lose their individuality?

NEET 2026 Solution View → 50

Which of the following structural modifications in a simple triglyceride molecule leads to the formation of a compound lipid such as lecithin?

NEET 2026 Solution View → 51

A chemical compound 'X' closely resembles a normal substrate 'S' in its molecular structure. When 'X' is introduced into a biological system, it competes with 'S' for the substrate

NEET 2026 Solution View → 52

Catalase and peroxidase are enzymes that catalyse the breakdown of hydrogen peroxide into water and oxygen. Which of the following acts as a tightly bound prosthetic group for thes

NEET 2026 Solution View → 53

In the given diagram of the outermost layers of a dicot stem, which labelled structure represents a typically multicellular epidermal appendage that helps in preventing water loss

NEET 2026 Solution View → 54

A mutant strain of E. coli is grown in a culture medium containing lactose as the sole carbon source. It is observed that lactose efficiently enters the bacterial cells, but the ce

NEET 2026 Solution View → 55

Observe the given diagram of a genetic cross and match the labels (P, Q, R, S) in List I with their correct genetic terms or values in List II. List I List II A Process P 1 Heteroz

NEET 2026 Solution View → 56

While analyzing a monohybrid cross between homozygous tall and dwarf pea plants, a student notes several genetic phenomena. Which of the following can be specifically explained on

NEET 2026 Solution View → 57

In Mirabilis jalapa , flower colour exhibits incomplete dominance. If a breeder wishes to obtain a progeny containing only pink and white flowers in a 1:1 phenotypic ratio, which o

NEET 2026 Solution View → 58

In garden pea, violet flower colour (V) is dominant over white flower colour (v). A researcher wishes to determine the exact genotype of a plant bearing violet flowers. Which of th

NEET 2026 Solution View → 59

During recombinant DNA procedures, the restriction endonuclease EcoRI is widely used to cut DNA molecules. Which of the following correctly represents the specific palindromic nucl

NEET 2026 Solution View → 60

As per the records of the IUCN Red List, which of the following recently extinct species was native to Russia?

NEET 2026 Solution View → 61

Read the following events and identify which of them represent the components of the 'Evil Quartet' responsible for the loss of biodiversity: A. Extinction of Steller's sea cow due

NEET 2026 Solution View → 62

Given below is a diagram showing four different types of placentation labeled A, B, C, and D. Match the figures in List I with their corresponding examples in List II. List I List

NEET 2026 Solution View → 63

Observe the given graph showing the concept of activation energy for a chemical reaction. Which of the following options correctly identifies the labels A, B, and C?

NEET 2026 Solution View → 64

Leucoplasts are colourless plastids of varied shapes and sizes that store different types of nutrients. Which of the following types of leucoplasts is specifically responsible for

NEET 2026 Solution View → 65

To prepare a weed-free lawn, gardeners extensively use a specific plant growth regulator that selectively kills dicotyledonous weeds but does not affect mature monocotyledonous pla

NEET 2026 Solution View → 66

During the continuous operation of the Krebs cycle, carbon is lost in the form of CO₂ . Which of the following intermediate conversions represents one of these decarboxylation even

NEET 2026 Solution View → 67

Observe the given graph representing the species-area relationship proposed by Alexander von Humboldt. Match the labels (A, B, C, D) in List I with their correct descriptions or eq

NEET 2026 Solution View → 68

In a terrestrial ecosystem, the Gross Primary Productivity (GPP) of the producers is 20,000 kcal m ⁻² yr ⁻¹ . If the producers utilize 20 % of this energy for their own respiration

NEET 2026 Solution View → 69

Observe the given diagrammatic representation of a specific muscle tissue. Identify the structure labeled 'X' and select the option that correctly pairs it with the primary locatio

NEET 2026 Solution View → 70

Dog fish and Angel fish are respectively known as

NEET 2026 Solution View → 71

Observe the given diagram showing a specific stage of meiotic cell division. Match List I (relative stages of this division) with List II (characteristic features) based on the dia

NEET 2026 Solution View → 72

Given below are two cross-sectional diagrams labeled as Figure X and Figure Y, representing specific cell organelles. Match the items in List I with their corresponding description

NEET 2026 Solution View → 73

Which of the following hormones acts principally on hepatocytes to stimulate both glycogenolysis and gluconeogenesis, thereby leading to hyperglycemia?

NEET 2026 Solution View → 74

Following is a list of structures through which a red blood cell passes as it travels from the right atrium to the systemic aorta: A. Bicuspid valve B. Aortic semilunar valve C. Tr

NEET 2026 Solution View → 75

Observe the given spirogram where specific respiratory capacities and volumes are indicated by brackets labeled A, B, C, and D. Match the labels in List I with their corresponding

NEET 2026 Solution View → 76

The oxygen dissociation curve is a sigmoid curve that illustrates the relationship between the partial pressure of oxygen and the percentage saturation of haemoglobin. Under which

NEET 2026 Solution View → 77

Observe the given diagram of the human skeleton where four specific joints are labeled as A, B, C, and D. Match the labeled joints in List I with their corresponding types in List

NEET 2026 Solution View → 78

All of the following structures are included in the female external genitalia, except:

NEET 2026 Solution View → 79

During transcription, the sequence of the template strand of a transcription unit is given as: 5' - C G A T A G C C G T A T G C A - 3' Which of the following represents the correct

NEET 2026 Solution View → 80

Given below are some key features of different stages in human evolution. Arrange the hominids possessing these features in the correct chronological sequence of their appearance o

NEET 2026 Solution View → 81

According to the Hardy-Weinberg principle, allele frequencies in a population are stable and remain constant from generation to generation. Which of the following conditions is ess

NEET 2026 Solution View → 82

In the E. coli cloning vector pBR322, the rop gene is responsible for:

NEET 2026 Solution View → 83

In a simple stirred-tank bioreactor, what is the primary function of its cylindrical shape or curved base?

NEET 2026 Solution View → 84

A foreign DNA fragment was ligated at the BamH I restriction site of the pBR322 cloning vector. The resulting recombinant plasmids were introduced into host E. coli cells. The sele

NEET 2026 Solution View → 85

Regarding the mechanism of competitive inhibition of an enzyme, arrange the following events in the correct logical sequence of cause and effect : A. The inhibitor competes with th

NEET 2026 Solution View → 86

During a blood typing test, a man's blood sample shows agglutination with both anti-A and anti-B sera. He marries a woman whose blood shows no agglutination with either sera. Which

NEET 2026 Solution View → 87

Given below is a reference to a diagrammatic representation of the evolutionary history of vertebrates through geological periods. Match the labels A, B, C, and D in List I with th

NEET 2026 Solution View → 88

According to the classification of pteridophytes, which of the following represents an incorrect match between the class and its corresponding example?

NEET 2026 Solution View → 89

In a typical angiospermic flower, the calyx, corolla, androecium, and gynoecium are successively arranged on the swollen terminal end of the pedicel. This swollen structure is know

NEET 2026 Solution View → 90

Assertion (A) : In a monocotyledonous stem, the vascular bundles are surrounded by a sclerenchymatous bundle sheath. Reason (R) : The ground tissue in a monocotyledonous stem is hi

NEET 2026 Solution View → 91

Identify the key difference between Anaphase I and Anaphase II during meiotic cell division.

NEET 2026 Solution View → 92

Which of the following stages of prophase I is characterised by the terminalisation of chiasmata?

NEET 2026 Solution View → 93

Which plant growth regulator is widely recognized as a stress hormone because it stimulates the closure of stomata and increases plant tolerance to various environmental stresses?

NEET 2026 Solution View → 94

In agricultural and horticultural practices, which of the following plant growth regulators is extensively used to initiate rooting in stem cuttings and induce parthenocarpy in tom

NEET 2026 Solution View → 95

During secondary growth in dicotyledonous stems, the fully differentiated parenchymatous cells of medullary rays regain the capacity to divide and form the interfascicular cambium.

NEET 2026 Solution View → 96

Farmers often face the economic burden of purchasing hybrid seeds every year because the seeds collected from hybrid plants lose their hybrid vigour in subsequent generations due t

NEET 2026 Solution View → 97

In 1953, S.L. Miller successfully simulated the conditions of primitive Earth in a laboratory setup to test the theory of chemical evolution. Which of the following was utilized by

NEET 2026 Solution View → 98

According to the widely accepted scheme of cellular respiration, which of the following pathways serves as the only process of respiration in anaerobic organisms?

NEET 2026 Solution View → 99

To fix 5 molecules of CO₂ during the Calvin cycle, what is the total number of ATP and NADPH molecules consumed respectively?

NEET 2026 Solution View → 100

The leaf mesophyll cells of an angiosperm contain 24 chromosomes. What will be the number of chromosomes in the synergid, zygote, and primary endosperm nucleus (PEN) of this plant,

NEET 2026 Solution View → 101

A plant species possesses well-exposed stamens, large feathery stigmas, and a single ovule in each ovary. The most likely agent of pollination for this plant is:

NEET 2026 Solution View → 102

In the methodology of the Human Genome Project, the blind approach of sequencing the whole set of genome that contained all the coding and non-coding sequences, and later assigning

NEET 2026 Solution View → 103

In eukaryotes, the primary transcript that acts as a precursor of mRNA, known as heterogeneous nuclear RNA (hnRNA), is synthesized by which of the following enzymes?

NEET 2026 Solution View → 104

During the biochemical characterization of Griffith's transforming principle, it was observed that the transformation of non-virulent R strain bacteria into virulent S strain was i

NEET 2026 Solution View → 105

Based on T.H. Morgan's experimental observations in Drosophila , which of the following statements correctly defines the term 'linkage'?

NEET 2026 Solution View → 106

A genetic disorder in humans is caused by a mutation in the gene that codes for the enzyme phenylalanine hydroxylase. This single gene mutation manifests in multiple phenotypic exp

NEET 2026 Solution View → 107

A mixture containing DNA fragments of sizes 150 bp , 450 bp , 900 bp , and 2500 bp is subjected to agarose gel electrophoresis. Which of these fragments will be found closest to th

NEET 2026 Solution View → 108

In the process of isolating DNA for recombinant DNA technology, which of the following enzymes is specifically used to break open fungal cells?

NEET 2026 Solution View → 109

Which of the following techniques involves the direct introduction of recombinant DNA into the nucleus of an animal cell?

NEET 2026 Solution View → 110

A genetic engineer isolates an autonomously replicating, extrachromosomal genetic element from a bacterial cell to use as a cloning vector. Which of the following represents the ty

NEET 2026 Solution View → 111

The extinction of the Passenger pigeon and Steller's sea cow in the last 500 years is a classic example of biodiversity loss primarily due to:

NEET 2026 Solution View → 112

A considerable amount of gross primary productivity is utilized by plants for their own metabolic needs. The remaining biomass, which is available for consumption to heterotrophs (

NEET 2026 Solution View → 113

Given below are some statements related to the process of decomposition in an ecosystem: A. Humification leads to the accumulation of a dark coloured amorphous substance which is h

NEET 2026 Solution View → 114

What is the net outcome of the photorespiratory pathway in C ₃ plants?

NEET 2026 Solution View → 115

During the light reaction of photosynthesis, the chemiosmotic hypothesis explains the mechanism of ATP synthesis. According to this hypothesis, what directly provides the energy th

NEET 2026 Solution View → 116

Given below are the key steps involved in the isolation of genetic material from a fungal cell. Arrange these steps in the correct sequence. A. Addition of chilled ethanol to the p

NEET 2026 Solution View → 117

Observe the ecological pyramid given below, which includes specific quantitative data for each trophic level. Which of the following ecosystems and parameters does this pyramid mos

NEET 2026 Solution View → 118

A physician using a stethoscope hears two prominent sounds during each cardiac cycle of a healthy individual. The second heart sound is produced primarily due to the:

NEET 2026 Solution View → 119

When an artificial electrical stimulus is applied to the middle of an axon, the action potential propagates in both directions along the membrane. However, at a chemical synapse, t

NEET 2026 Solution View → 120

After a normal expiration, a certain volume of air remains in the human lungs. Which of the following correctly represents this volume?

NEET 2026 Solution View →
Practice all Chapter questions in the app →