NEET 2023 Biology Questions

Given below are two statements: Statement I: During G0 phase of cell cycle, the cell is metabolically inactive. Statement II: The centrosome undergoes duplication during S phase of interphase. [] Choose the correct answer:

Doubling of the number of chromosomes can be achieved by disrupting mitotic cell division soon after: [ ]

During which stages of mitosis and meiosis, respectively, does the centromere of each chromosome split? [ ]

Match List I with List II: List I A. M 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. Equational division Choose the correct answer: []

Select the correct statements: 1. Tetrad formation is seen during Leptotene. 2. During Anaphase, the centromeres split and chromatids separate. 3. Terminalization takes place during Pachytene. 4. Nucleolus, Golgi complex and ER are reformed during Telophase. 5. Crossing over takes place between sister chromatids of homologous chromosome. []

Which one of the following is the quiescent stage of the cell cycle?[ ]

The process of appearance of recombination nodules occurs at which substage of Prophase I in meiosis? []

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

The dissolution of synaptonemal complex occurs during:[]

Cellulose does not form blue colour with iodine because []

Inulin is a polymer of: ()

Q29. Match List – I with List – II [] List I (Biomolecule) A. Protein B. Unsaturated fatty acid C. Nucleic acid D. Polysaccharide List II (Bond type) I. C=C double bonds II. Phosphodiester bond III. Glycosidic bonds IV. Peptide bonds Choose the correct answer:

Given below are two statements: [] Statement I: A protein is imagined as a line, the left end represented by first amino acid (C-terminal) and the right end represented by last amino acid (N-terminal). Statement II: Adult human haemoglobin consists of 4 subunits (two subunits of α type and two subunits of β type). Which of the following is correct?

Given below are two statements: [] Statement I: Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat. Statement II: When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of enzyme, it is known as competitive inhibitor.

Which of the following is not a secondary metabolite? ()

Malonate inhibits the growth of pathogenic bacteria by inhibiting the activity of: []

Family Fabaceae differs from Solanaceae and Liliaceae. With respect to stamens, which feature is specific to Fabaceae only? []

Match the following flower types with correct examples: (A) Zygomorphic — (B) Hypogynous — (C) Perigynous — (D) Epigynous — (I) Mustard (II) Plum (III) Cassia (IV) Cucumber Select the correct option: [ ]

Axile placentation is observed in: []

In Calotropis, aestivation is: []

In a pea flower, five petals are arranged in a specialized manner with one posterior, two lateral and two anterior. These are named as __, __ and __ respectively. [ ]

Assertion (A): A flower is defined as modified shoot wherein the shoot apical meristem changes to floral meristem. Reason (R): Internode of the shoot gets condensed to produce different floral appendages laterally at successive node instead of leaves. []

The reaction centre in PS II has an absorption maxima at ()

How many ATP and NADPH₂ are required for the synthesis of one molecule of glucose during Calvin cycle? ()

Given below are two statements: () Statement I: RuBisCO is the most abundant enzyme in the world. Statement II: Photorespiration does not occur in C₄ plants. Choose the most appropriate answer:

Which of the following combinations is required for chemiosmosis? ()

Which of the following statements is incorrect? ()

() Match List-I with List-II

Given below are two statements: () Statement I: In prokaryotes, the positively charged DNA is held with some negatively charged proteins in a region called nucleoid. Statement II: In eukaryotes, the negatively charged DNA is wrapped around the positively charged histone octamer to form nucleosome.

Which of the following is not a cloning vector? ()

The salient features of genetic code include: () (A) The code is palindromic (B) UGA acts as initiator codon (C) The code is unambiguous and specific (D) The code is nearly universal Choose the correct option:

How many different proteins does the ribosome consist of? ()

Given below are two statements: () I: The process of copying genetic information from one strand of the DNA into RNA is termed as transcription. II: A transcription unit in DNA is defined primarily by the three regions in the DNA i.e. a promoter, the structural gene, and a terminator. Choose the correct answer:

Which scientist conducted an experiment with ³²P and ³⁵S labelled phages for demonstrating that DNA is the genetic material? ()

Which one of the following acts as an inducer for lac operon? ()

The last chromosome sequenced in the Human Genome Project was: ()

If the sequence on mRNA formed is 5’-AUCGAUCGAUCGAUCGAUCGAUCGAUCG-3’, what is the sequence on the corresponding coding strand? ()

With reference to Hershey and Chase experiments, select the correct statements: () A: Viruses grown in the presence of radioactive phosphorus contained radioactive DNA. B: Viruses grown on radioactive sulphur contained radioactive proteins. C: Viruses grown on radioactive phosphorus contained radioactive protein. D: Viruses grown on radioactive sulphur contained radioactive DNA. E: Viruses grown on radioactive protein contained radioactive DNA. Choose the correct option:

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

Given below are two statements: () Statement I: RNA mutates at a faster rate. Statement II: Viruses having RNA genome and shorter life span mutate and evolve faster. Choose the correct answer:

Unequivocal proof that DNA is the genetic material was first proposed by: ()

Given below are two statements: () Statement I: RNA being unstable, it mutates at a faster rate. Statement II: RNA can directly code for synthesis of proteins hence can easily express the characters. Choose the correct answer:

Match List I with List II: () List I List II A. gene ‘a’ I. β-galactosidase B. gene ‘y’ II. Transacetylase C. gene ‘i’ III. Permease D. gene ‘z’ IV. Repressor protein

Expressed Sequence Tags (ESTs) refers to: ()

The component that binds to the operator region of an operon and prevents RNA polymerase from transcribing the operon is: ()

Thermostable DNA polymerase used in PCR was isolated from: ()

Which of the following statement is incorrect about Agrobacterium tumefaciens? ()

Ligation of foreign DNA at which of the following site will result in loss of tetracycline resistance of pBR322? ()

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

Main steps in the formation of Recombinant DNA are given below. Arrange these steps in a correct sequence. () A. Insertion of recombinant DNA into the host cell B. Cutting of DNA at specific location by restriction enzyme C. Isolation of desired DNA fragment D. Amplification of gene of interest using PCR

In gene gun method used to introduce alien DNA into host cells, microparticles of ___________ metal are used. ()

Which of the following is not a cloning vector? ()

Upon exposure to UV radiation, DNA stained with ethidium bromide will show: ()

Which of the following can act as molecular scissors? ()

[] In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are:

[] Large, colourful, fragrant flowers with nectar are seen in:

What is the function of tassels in the corn cob? ()

In angiosperms, the correct sequence of events leading to the formation of female gametophyte in the ovule is: () A. 3 successive free nuclear divisions in functional megaspore. B. Degeneration of 3 megaspores. C. Meiotic division in megaspore mother cell. D. Migration of 3 nuclei towards each pole. E. Formation of a wall resulting in seven-celled embryo sac.

In which of the following sets of families, the pollen grains are viable for months? ()

[ - Assertion Reason] Assertion (A): In gymnosperms, the pollen grains are released from the microsporangium and carried by air currents. Reason (R): Air currents carry the pollen grains to the mouth of the archegonia where the male gametes are discharged and pollen tube is not formed.

Transfer of pollen grains from anther to stigma of another flower of the same plant is known as: ()

Match List I with List II. ()

Given below are two statements: () I: Intra Cytoplasmic Sperm Injection (ICSI) is another specialized procedure of in-vivo fertilization. II: Infertility cases due to the inability of the male partner to inseminate the female can be corrected by Artificial Insemination (AI). Choose the correct answer from the options given below:

Which of the following sexually transmitted infections are completely curable? ()

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. () Assertion A: Amniocentesis for sex determination is one of the strategies of Reproductive and Child Health Care Programme. Reason R: Ban on amniocentesis checks increasing menace of female foeticide. In the light of the above statements, choose the correct answer from the options given below:

Which of the following common sexually transmitted diseases is completely curable when detected early and treated properly? ()

Match List I with List II ()

Which of the following statements are correct? () A. Reproductive health refers to total well-being in all aspects of reproduction B. Amniocentesis is legally banned for sex determination in India C. "Saheli" – an oral contraceptive for females was developed in collaboration with ICMR (New Delhi) D. Amniocentesis is used to determine genetic disorders and survivability of foetus Choose the most appropriate answer:

For chemical defense against herbivores, Calotropis has: ()

There are 250 snails in a pond, and within a year their number increases to 2500 by reproduction. What should be their birth rate (in per snail per year)? ()

Match List-I with List-II: () List-I (Population Term) A. Logistic growth B. Exponential growth C. Expanding age pyramid D. Stable age pyramid List-II I. Unlimited resource availability condition II. Limited resource availability condition III. % individuals: Pre > Reproductive > Post IV. % individuals: Pre ≈ Reproductive

Match List-I with List-II: () List-I (Interacting Species) A. A Leopard and a Lion in a forest/grassland B. A cuckoo laying eggs in crow’s nest C. Fungi and root of higher plant in mycorrhizae D. A cattle egret and cattle in a field List-II (Interaction Type) I. Competition II. Brood parasitism III. Mutualism IV. Commensalism Choose the correct answer:

Match List-I with List-II: () List-I (Interaction) A. Mutualism B. Commensalism C. Amensalism D. Parasitism List-II (Effect) I. + (A), O (B) II. – (A), O (B) III. + (A), – (B) IV. + (A), + (B) Choose the correct option:

Given below are two statements: () Statement I: Gause's Competitive Exclusion Principle states that two closely related species competing for the same resources cannot co-exist indefinitely, and the competitively inferior one will be eliminated eventually. Statement II: In general, carnivores are more adversely affected by competition than herbivores. In the light of the above statements, choose the correct answer from the options given below:

Plants offer rewards to animals in the form of pollen and nectar, and the animals facilitate the pollination process. This is an example of: ()