NEET 2021 Biology Questions

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

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

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?

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

The centriole undergoes duplication during:

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

Match List-I with List-II: List-I (a) S phase (b) G2 phase (c) Quiescent stage (d) G1 phase List-II (i) Proteins are synthesized (ii) Inactive phase (iii) Interval between mitosis and initiation of DNA replication (iv) DNA replication Choose the correct answer from the options given below:

Which of the following statements is true?

Which of the following statements is correct?

Which of the following algae produce Carrageen?

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

Which of the following plants is monoecious?

Gemmae are present in:

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

Which of the following statements is incorrect?

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

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

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

Match List I with List II. List I (a) Scapula (b) Cranium (c) Sternum (d) Vertebral column List II (i) Cartilaginous joints (ii) Flat bones (iii) Fibrous joints (iv) Triangular flat bone Choose the correct answer from the options given below:

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

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

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

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

Given below are two statements: 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. In the light of the above statements, 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. In the light of the above statements, choose the correct answer from the options given below:

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

Match list I with list II. List I: (a) Protein; (b) Unsaturated fatty acid; (c) Nucleic acid; (d) Polysaccharide List II: (i) C=C double bonds; (ii) Phosphodiester bonds; (iii) Glycosidic bonds; (iv) Peptide bonds

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. (e) Arachidonic acid has 16 carbon atoms. Choose the correct answer from the options given below

Identify the incorrect pair.

Which of the following are not secondary metabolites in plants?

Which of the following statements is incorrect?

Which out of the following statements is incorrect?

The first stable product of CO2 fixation in sorghum is:

Which of the following statements is not correct?

Match List-I with List-II: List I (a) Cristae (b) Thylakoid (c) Centromere (d) Cisternae List II (i) Primary constriction in chromosome (ii) Disc-shaped sacs in Golgi apparatus (iii) Infoldings in mitochondria (iv) Flattened membranous sacs in stroma of plastids Choose the correct answer from the options given below:

The organelles that are included in the endomembrane system are

Which of the following statements is not correct?

The plant hormone used to destroy weeds in a field is

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

Which of the following statements is correct

Which of the following statements is incorrect?

Which of the following statements is incorrect?

Match List I with List II. List I (a) Metamerism (b) Canal system (c) Comb plates (d) Cnidoblasts List II (i) Coelenterata (ii) Ctenophora (iii) Annelida (iv) Porifera Choose the correct option from those given below.

Read the following statements. 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.

Which of the following statements wrongly represents the nature of smooth muscle? (a) Communication among the cells is performed by intercalated discs (b) These muscles are present in the wall of blood vessels (c) These muscle have no striations (d) They are involuntary muscles Choose the correct answer:

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

Match the floral formulae in List I with the families in List II. List I (Floral formula) (a) % ⚥ K(5) C1+2+(2) A(9)+1 G1 (b) ⊕ ⚥ K(5) C(5) A5 G(2) (c) ⊕ ⚥ P(3+3) A(3+3) G(3) (d) ⊕ ⚥ K2+2 C4 A2+4 G(2) List II (Family) (i) Brassicaceae (ii) Liliaceae (iii) Fabaceae (iv) Solanaceae Choose the correct answer from the options given below. (NEET 2021)

Diadelphous stamens are found in:

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

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

Which of the following statements is correct?

Match List-I with List-II. List-I: (a) Cells with active cell division capacity (b) Tissue having all cells similar in structure and function (c) Tissue having different type of cells (d) Dead cells with highly thickened walls and narrow lumen List-II: (i) Vascular Tissues (ii) Meristematic tissues (iii) Sclereids (iv) Simple Tissue Choose the correct answer:

Which of the following statements is not correct?

Which of the following statements is incorrect?

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

Which is the “Only enzyme” that has “Capability” to catalyse Initiation, Elongation and Termination in the process of transcription in prokaryotes?

Complete the flow chart on central dogma. (a) ____ (b) ____ (c) ____ (d) ____ (The flow chart shows DNA, with a self-directed arrow (a) back to DNA, an arrow (b) from DNA to RNA, an arrow (c) from RNA to (d).) a. (a)-Replication; (b)-Transcription; (c)-Translation; (d)-Protein b. (a)-Transduction; (b)-Translation; (c)-Replication; (d)-Protein c. (a)-Replication; (b)-Transcription; (c)-Transduction; (d)-Protein d. (a)-Translation; (b)-Replication; (c)-Transcription; (d)-Transduction

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

Identify the correct statement. a. The coding strand in a transcription unit is copied to an mRNA b. Split gene arrangement is characteristic of prokaryotes c. In capping, methyl guanosine triphosphate is added to the 3’ end of hnRNA. d. RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria.

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

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

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

Which of the following statements is not correct?

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 from the options given below. (NEET 2021)

Now a days 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 because : (NEET 2021)

When gene targetting involving gene amplification is attempted in an individual's tissue to treat disease, it is known as: (NEET 2021)

The Adenosine deaminase deficiency results into:

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? (NEET 2021)

Which or the following statements is incorrect?

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

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

Plasmid pBR322 has PsI restriction enzyme site within gene ampR that confers ampicillin resistance. If this enzyme is used for inserting a gene for β-galactoside production and the recombinant plasmid is inserted in a E.coli strain

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

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

The production of gametes by the parents, the formation of zygotes, the F1 and F2 plants, can be understood using

The production of gametes by the parents, formation of zygotes, the F1 and F2 plants can be understood from a diagram called

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

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

Which of the following statements is not correct?

In the equation GPP - R = NPP R represents

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

Amensalism can be represented as :

Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival? (NEET 2021)

In the exponential growth equation Nt = N0e^rt, e represents:

Now a days 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 because:

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

Match list I with list II. List I (a) Filariasis (b) Amoebiasis (c) Pneumonia (d) Ringworm List II (i) Haemophilus influenzae (ii) Trichophyton (iii) Wuchereria bancrofti (iv) Entamoeba histolytica

Which of the following secretes the hormone, relaxin, during the later phase of pregnancy? (NEET 2021)

Receptors for sperm binding in mammals are present on

Which of these is not an important component of initiation of parturition in humans? (NEET 2021)

Which of the following statements is not true ?

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

Match list I with list II. List I | List II (a) Adaptive radiation | (i) Selection of resistant varieties due to excessive use of herbicides and pesticides (b) Convergent evolution | (ii) Bones of forelimbs in Man and Whale (c) Divergent evolution | (iii) Wings of butterfly and birds (d) Evolution by anthropogenic action | (iv) Darwin Finches Choose the correct answer from the options given below

A typical angiosperm embryo sac at maturity is

In some members of which of the following pairs of families, pollen grains retain their viability for months after release ? (NEET 2021)

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: (NEET 2021)

Which one of the following is an example of Hormone releasing IUD? (NEET 2021)

Match list I with list II. List I (a) Vaults (b) IUDs (c) Vasectomy (d) Tubectomy List II (i) Entry of sperm through Cervix is blocked (ii) Removal of Vas deferens (iii) Phagocytosis of sperms within the Uterus (iv) Removal of fallopian tube Choose the correct answer from the options given below. (NEET 2021)

Match list I with list II. List I (Microorganism) — List II (Product): (a) Aspergillus niger (b) Acetobacter aceti (c) Clostridium butylicum (d) Lactobacillus (i) Acetic Acid (ii) Lactic Acid (iii) Citric Acid (iv) Butyric Acid