NEET 2021
Previous Year Questions

The RBC deficiency disease is deficiency disease of:

Which of the following statements is not correct?

Which of the following plants is monoecious?

The first stable product of $CO_2$ fixation in Sorghum is

Diadelphous stamens are found in

DNA strands on a gel stained with ethidium bromide when viewed under UV radiation, appear as

Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called

Match List-I with List-II

In the equation GPP - R = NPP, R represents:

The production of gametes by the parents, formation of zygotes, the $F_1$ and $F_2$ plants, can be understood from a diagram called:

Which of the following is an incorrect statement?

Match List-I with List-II.

The amount of nutrients such as carbon, nitrogen, phosphorus and calcium present in the soil at any given time is referred as:

The term used for transfer of pollen grains from anthers of one plant to stigma of a different plant which, during pollination, brings genetically different types of pollen grains to stigma, is:

Which of the following stages of meiosis involves division of centromere?

Which of the following is a correct sequence of steps in a PCR (Polymerase Chain Reaction)?

When gene targeting involving gene amplification is attempted in an individual's tissue to treat disease, it is known as:

Match List-I with List-II. Choose the correct answer from the options given below:

The factor that leads to Founder effect in a population is:

When the centromere is situated in the middle of two equal arms of chromosomes, the chromosome is referred as:

Gemmae are present in:

During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out:

Match List-I with List-II. Choose the correct answer from the options given below.

The site of perception of light in plants during photoperiodism is:

The plant hormone used to destroy weeds in a field is:

Which of the following algae produce carrageen?

Complete the flow chart on central dogma.

Which of the following are not secondary metabolites in plants?

Inspite of interspecific competition in nature, which mechanism did the competing species might have evolved for their survival?

Which of the following is not an application of PCR (Polymerase Chain Reaction)?

Match List-I with List-II. Select the correct answer from the options given below

A typical angiosperm embryo sac at maturity is:

Which of the following algae contains mannitol as reserve food material?

Genera like Selaginella and Salvinia produce two kinds of spores. Such plants are known as:

Mutations in plant cells can be induced by:

Amensalism can be represented as:

What is the role of RNA polymerase III in the process of transcription in eukaryotes?

Select the correct pair.

Plasmid pBR322 has PstI restriction enzyme site within gene amp^r that confers ampicillin resistance. If this enzyme is used for inserting a gene for β-galactosidase production and the recombinant plasmid is inserted in an E.coli strain:

DNA fingerprinting involves identifying differences in some specific regions in DNA sequence, called as:

In the exponential growth equation $N_t = N_0 e^{rt}$, $e$ represents:

Which of the following statements is incorrect?

Which of the following statements is correct?

Match Column-I with Column-II. Choose the correct answer from the options given below.Match Column-I with Column-II. Choose the correct answer from the options given below.

Which of the following statements is incorrect?

In some members of which of the following pairs of families, pollen grains retain their viability for months after release?

Identify the correct statement.

Match Column-I with Column-II.

Match List-I with List-II. Choose the correct answer from the options given below.Match List-I with List-II. Choose the correct answer from the options given below.

Nowadays it is possible to detect the mutated gene causing cancer by allowing radioactive probe to hybridise its complementary DNA in a clone of cells, followed by its detection using autoradiography. The mutated gene is detected because:

Erythropoietin hormone which stimulates R.B.C. formation is produced by:

Which of the following characteristics is incorrect with respect to cockroach?

Succus entericus is referred to as:

Which stage of meiotic prophase shows terminalisation of chiasmata as its distinctive feature?

The partial pressures (in mm Hg) of oxygen (O₂) and carbon dioxide (CO₂) at alveoli (the site of diffusion) are:

Match the following: Choose the correct answer from the options given below.Match the following: Choose the correct answer from the options given below.

During the process of gene amplification using PCR, if very high temperature is not maintained in the beginning, then which of the following steps of PCR will be affected first?

Match List-I with List-II: Choose the correct answer from the options given below.

Which of the following statements wrongly represents the nature of smooth muscle?

Chronic autoimmune disorder affecting neuromuscular junction leading to fatigue, weakening and paralysis of skeletal muscle is called:

Persons with 'AB' blood group are called as 'Universal recipients'. This is due to:

The fruit fly has 8 chromosomes (2n) in each cell. During interphase of mitosis if the number of chromosomes at G₁ phase is 8, what would be the number of chromosomes after S phase?

Receptors for sperm binding in mammals are present on:

Which one of the following belongs to the family Muscidae?

Identify the incorrect pair:

Venereal diseases can spread through:(a) Using sterile needles (b) Transfusion of blood from infected person (c) Infected mother to foetus (d) Kissing (e) Inheritance Choose the correct answer.

The organelles that are included in the endomembrane system are:

For effective treatment of the disease, early diagnosis and understanding its pathophysiology is very important. Which of the following molecular diagnostic techniques is very useful for early detection? (1) Hybridization Technique (2) Western Blotting Technique (3) Southern Blotting Technique (4) ELISA Technique

With regard to insulin choose correct options. (a) C-peptide is not present in mature insulin. (b) The insulin produced by rDNA technology has C-peptide. (c) The pro-insulin has C-peptide. (d) A-peptide and B-peptide of insulin are interconnected by disulphide bridges. Choose the correct answer.

A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is:

Which is the 'Only enzyme' that has capability to catalyse initiation, elongation and termination in the process of transcription in prokaryotes?

Which one of the following organisms bears hollow and pneumatic long bones?

Read the following statements: (a) Metagenesis is observed in Helminths. (b) Echinoderms are triploblastic and coelomate animals. (c) Round worms have organ-system level of body organization. (d) Comb plates present in ctenophores help in digestion. (e) Water vascular system is characteristic of Echinoderms. Choose the correct answer from the options given below.

Match List-I with List-II. Choose the correct answer from the options given below.

Sphincter of Oddi is present at:

If Adenine makes 30% of the DNA molecule, what will be the percentage of Thymine, Guanine and Cytosine in it?

Match List-I with List-II. Choose the correct answer from the options given below.

Which enzyme is responsible for the conversion of inactive fibrinogens to fibrins?

Which of the following is not an objective of biofortification in crops?

Dobson units are used to measure thickness of:

Which one of the following is an example of Hormone releasing IUD?

The centriole undergoes duplication during:

Which of the following RNAs is not required for the synthesis of protein?

In a cross between a male and female, both heterozygous for sickle cell anaemia gene, what percentage of the progeny will be diseased?

Select the favourable conditions required for the formation of oxyhaemoglobin at the alveoli.

Match List-I with List-II: Choose the correct answer from the options given below.

Match List-I with List-II and choose the correct answer from the options given below:

Which of these is not an important component of initiation of parturition in humans?

Which one of the following statements about Histones is wrong?

During muscular contraction which of the following events occur? (a) 'H' zone disappears (b) 'A' band widens (c) 'I' band reduces in width (d) Myosin hydrolyzes ATP, releasing ADP and Pi (e) Z-lines attached to actins are pulled inwards Choose the correct answer from the options given below:

Match List-I with List-II: Choose the correct answer from the options given below:

Assertion (A): A person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations. Reason (R): Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen. Choose the correct answer:

The Adenosine deaminase deficiency results into:

Which of the following is not a step in Multiple Ovulation Embryo Transfer Technology (MOET)?

Match List-I with List-II Choose the correct answer from the options given below.

Following are the statements with reference to lipids: (a) Lipids having only single bonds are called unsaturated fatty acids. (b) Lecithin is a phospholipid. (c) Trihydroxy propane is glycerol. (d) Palmitic acid has 20 carbon atoms including carboxyl carbon. Choose the correct answer from the options given below.

Following are the statements about prostomium of earthworm: (a) It serves as a covering for mouth. (b) It helps to open cracks in the soil into which it can crawl. (c) It is one of the sensory structures. (d) It is the first body segment. Choose the correct answer from the options given below.

Which of the following secretes the hormone relaxin, during the later phase of pregnancy?

Statement I: The codon 'AUG' codes for methionine and phenylalanine. Statement II: 'AAA' and 'AAG' both codons code for the amino acid lysine. In the light of the above statements, choose the correct answer from the options given below.

Identify the types of cell junctions that help to stop leakage of substances across a tissue and facilitate communication with neighbouring cells via rapid transfer of ions and molecules.

Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are:

Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of:

Choose the correct option for graphical representation of Boyle's law, which shows a graph of pressure vs. volume of a gas at different temperatures:

The right option for the statement 'Tyndall effect is exhibited by', is:

The structures of beryllium chloride in solid state and vapour phase, are:

Tritium, a radioactive isotope of hydrogen, emits which of the following particles?

The major product formed in dehydrohalogenation reaction of 2-Bromo pentane is Pent-2-ene. This product formation is based on?

BF₃ is planar and electron deficient compound. Hybridization and number of electrons around the central atom, respectively are:

What is the IUPAC name of the organic compound formed in the following chemical reaction?

The molar conductance of NaCl, HCl and CH₃COONa at infinite dilution are 126.45, 426.16 and 91.0 S cm² mol⁻¹ respectively. The molar conductance of CH₃COOH at infinite dilution is:

The incorrect statement among the following is:

Statement I: Acid strength increases in the order given as HF << HCl << HBr << HI. Statement II: As the size of elements F, Cl, Br, I increases down the group, the bond strength of HF, HCl, HBr and HI decreases and so acid strength increases. In the light of the above statements, choose the correct answer from the options given below.

The correct structure of 2,6-Dimethyl-dec-4-ene is:

The correct sequence of bond enthalpy of C-X bond is:

The $pK_b$ of dimethylamine and $pK_a$ of acetic acid are 3.27 and 4.77 respectively at T (K). The correct option for the pH of dimethylammonium acetate solution is:

The following solutions were prepared by dissolving $10\,g$ of glucose $(C_6H_{12}O_6)$ in $250\,mL$ of water $(P_1)$, $10\,g$ of urea $(CH_4N_2O)$ in $250\,mL$ of water $(P_2)$ and $10\,g$ of sucrose $(C_{12}H_{22}O_{11})$ in $250\,mL$ of water $(P_3)$. The right option for the decreasing order of osmotic pressure of these solutions is:

The correct option for the number of body centred unit cells in all 14 types of Bravais lattice unit cells is:

The maximum temperature that can be achieved in blast furnace is:

For a reaction A → B, enthalpy of reaction is −4.2 kJ mol⁻¹ and enthalpy of activation is 9.6 kJ mol⁻¹. The correct potential energy profile for the reaction is shown in option:

The compound which shows metamerism is: