NEET-UG SERIES

Biology

The Molecular Basis Of Inheritance

70 previous year questions.

Volume: 70 Ques

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Chapter Questions
70 MCQs

01

PYQ 1989

medium

biology ID: neet-ug-

Diploid chromosome number in human is

1

46

2

44

3

48

4

42

02

PYQ 1993

medium

biology ID: neet-ug-

During DNA replication, the strands separate by

1

DNA polymerase

2

topoisomerase

3

unwindase/helicase

4

gyrase

03

PYQ 1993

medium

biology ID: neet-ug-

Nucleotide arrangement in DNA can be seen by

1

X-ray crystallography

2

electron microscope

3

ultracentrifuge

4

light microscope.

04

PYQ 1995

medium

biology ID: neet-ug-

Barr body in mammals represents

1

all the heterochromatin in male and female cells

2

the Y-chromosome in somatic cells of male i

3

all the heterochromatin in female cells

4

one of the two X-chromosomes in somatic cells of females. \

05

PYQ 1995

medium

biology ID: neet-ug-

Each chromosome at the anaphase stage of a bone marrow cell in our body has

1

two chromatids

2

several chromatids

3

no chromatids

4

only one chromatid.

06

PYQ 1999

medium

biology ID: neet-ug-

DNA is mainly found in

1

nucleolus

2

nucleus only

3

cytoplasm only

4

none of these.

07

PYQ 2000

medium

biology ID: neet-ug-

Anticodon occurs in

1

t-RNA

2

m-RNA

3

r-RNA

4

DNA.

08

PYQ 2000

medium

biology ID: neet-ug-

Extranuclear DNA is found in

1

lysosome and chloroplast

2

chloroplast and mitochondria

3

mitochrondria and lysosome

4

golgi and E.R.

09

PYQ 2000

medium

biology ID: neet-ug-

Most of the mutations are

1

harmful

2

harmful and recessive

3

beneficial

4

dominant.

10

PYQ 2000

medium

biology ID: neet-ug-

Irregularity is found in drosophila during the organ differentiation for example-inplace of wing, long legs are formed. Which gene is responsible for:

1

Double dominant gene

2

Homeotic gene

3

Complimentary gene

4

Plastid

11

PYQ 2000

medium

biology ID: neet-ug-

Similarity in DNA and RNA:

1

Both are polymer of nucleotides

2

Both have similar pyrimidine

3

Both have similar sugar

4

Both are genetic material

12

PYQ 2000

medium

biology ID: neet-ug-

Length of one loop of B-DNA:

1

2

3

4

13

PYQ 2000

medium

biology ID: neet-ug-

Which of the following is initiation codon:

1

UAG

2

AUC

3

AUG

4

CCU

14

PYQ 2000

medium

biology ID: neet-ug-

Genes for cytoplasmic male sterility in plants are generally located in:

1

Chloroplast genome

2

Mitochondrial genome

3

Nuclear-genome

4

Cytosol

15

PYQ 2001

easy

biology ID: neet-ug-

Ratio of complementary genes is

1

0.3771296296

2

0.5020949074

3

9: 3: 3:4

4

9:7.

16

PYQ 2001

medium

biology ID: neet-ug-

Extranuclear inheritance occurs in

1

killer Paramaecium

2

killer Amoeba

3

Euglena

4

Hydra.

17

PYQ 2001

medium

biology ID: neet-ug-

m-RNA is synthesised on DNA template in which direction

1

5' ? 3'

2

3' ? 5'

3

both a and b

4

any.

18

PYQ 2002

easy

biology ID: neet-ug-

Which of the following occurs more than one and less than five in a chromosome :-

1

Chromatid

2

Chromosome

3

Centromere

4

Telomere.

19

PYQ 2002

medium

biology ID: neet-ug-

Change in sequence of nucleotide in DNA is called as -

1

Mutagen

2

Mutation

3

Recombination

4

Translation

20

PYQ 2002

medium

biology ID: neet-ug-

Exon part of mRNAs have code for :-

1

Protein

2

Lipid

3

Carbohydrate

4

Phospholipid.

21

PYQ 2002

medium

biology ID: neet-ug-

Transformation experiment was first performed on which bacteria:-

1

E. coli

2

Diplococcus pneumoniae

3

Salmonella

4

Pasteurella pestis

22

PYQ 2002

medium

biology ID: neet-ug-

Which steroid is used for transformation

1

Cortisol

2

Cholesterol

3

Testosteron

4

Progesteron

23

PYQ 2002

medium

biology ID: neet-ug-

Nucleus of a donor embryonal cell/somatic cell is transferred to an enucleated egg cell. Then after the formation of the organism, what shell is true

1

Organism will have extranuclear genes of the donor cell

2

Organism will have extra nuclear genes of recipient cell

3

Organism will have extra nuclear genes of both donor and recipient cell

4

Organism will have nuclear genes of recipient cell

24

PYQ 2002

medium

biology ID: neet-ug-

Which of the following reunites the exon segments after RNA splicing?

1

RNA polymerase

2

RNA primase

3

RNA ligase

4

RNA proteoses.

25

PYQ 2002

medium

biology ID: neet-ug-

Which of the following enzymes are used to join bits of DNA :-

1

Ligase

2

Primase

3

DNA polymerase

4

Endonuclease.

26

PYQ 2002

medium

biology ID: neet-ug-

Out of 64 codons, 61 codons code for 20 types of amino acid. It is called :-

1

Degeneracy of genetic code

2

Overlapping of gene

3

Wobbling of codon

4

Universility of codons.

27

PYQ 2003

medium

biology ID: neet-ug-

During translation initiation in prokaryotes, a GTP molecule is needed in

1

Formation of formyl-met-tRNA

2

Binding of 30S subunit of ribosome with mRNA

3

Association of 30 S-mRNA with formyl-met-tRNA

4

Association of 50 S subunit of ribosome with initiation complex

28

PYQ 2003

medium

biology ID: neet-ug-

Degeneration of a genetic code is attributed to the

1

First member of a codon

2

Second member of codon

3

Entire codon

4

Third member of a codon

29

PYQ 2003

medium

biology ID: neet-ug-

In recent years,DNA sequences (nucleotide sequence) of mt-DNA and Y chromosomes were considered for the study of human evolution,because:

1

They are small,and therefore,easy to study

2

They are uniparental in origin and do not take part in recombination

3

Their structure is known in greater detail

4

They can be studied from the samples of fossil remains

30

PYQ 2004

medium

biology ID: neet-ug-

DNA fingerprinting refer to

1

Molecular analysis of profiles of DNA samples

2

Analysis of DNA samples using imprinting devices

3

Techniques used for molecular analysis of different specimens of DNA

4

Techniques used for identification of fingerprints of individuals.

31

PYQ 2004

medium

biology ID: neet-ug-

Extranuclear inheritance is the consequence of presence of genes in

1

Mitochondria and chloroplasts

2

Endoplasmic reticulum and mitochondria

3

Ribosomes and chloroplast

4

Lysosomes and ribosomes.

32

PYQ 2004

medium

biology ID: neet-ug-

The following ratio is generally constant for a species

1

A + G / C + T

2

T + C / G + A

3

G + C / A + T

4

A + C / T + G

33

PYQ 2004

medium

biology ID: neet-ug-

Which form of RNA has a structure resembling clover leaf

1

rRNA

2

hnRNA

3

mRNA

4

tRNA

34

PYQ 2006

medium

biology ID: neet-ug-

Amino acid sequence, in protein synthesis is decided by the sequence of-

1

r-RNA

2

t-RNA

3

m-RNA

4

c-DNA

35

PYQ 2006

medium

biology ID: neet-ug-

Antiparallel strands of a DNA molecule means that

1

One strand turns anti-clockwise

2

The phosphate groups of two DNA strands at their ends, share the-same position

3

The phosphate groups at the start of two DNA strands are in opposite position (pole)

4

One strand turns clockwise

36

PYQ 2006

medium

biology ID: neet-ug-

In which mode of inheritance do you expec more maternal influence among the offspring ?

1

Autosomal

2

Cytoplasmic

3

Y-linked

4

X-linked

37

PYQ 2007

medium

biology ID: neet-ug-

During transcription, polymerase holoenzyme binds to a gene promoter and assumes a saddle-like structure. What is it's -binding sequence ?

1

TATA

2

TTAA

3

AATT

4

CACC

38

PYQ 2007

medium

biology ID: neet-ug-

A sequential expression of a set of human genes occurs when a steroid molecule binds to the:-

1

Ribosome

2

Transfer RNA

3

Messenger RNA

4

DNA sequence

39

PYQ 2009

easy

biology ID: neet-ug-

Semi-conservative replication of DNA was first demonstrated in

1

Eschenchia coli

2

Streptococcus pneumonia

3

Drosophila melanogaster

4

Salmonella typhimurium

40

PYQ 2012

medium

biology ID: neet-ug-

Ribosomal RNA is actively synthesized in

1

Lysosomes

2

Nucleolus

3

Nucleoplasm

4

Ribosomes

41

PYQ 2013

medium

biology ID: neet-ug-

In an inducible operon, the genes are

1

usually not expressed unless a signal turns them on.

2

usually expressed unless a signal turns them 'off'.

3

never expressed

4

always expresser

42

PYQ 2013

medium

biology ID: neet-ug-

Which enzyme's will be produced in a cell in which there is a nonsense mutation in the lac Y gene ?

1

Lactose permease and transacetylase

2

?-galactosidase

3

Lactose permease

4

Transacetylase

43

PYQ 2013

medium

biology ID: neet-ug-

Which of the following is not a property of the genetic code?

1

Non-overlapping

2

Ambiguous

3

Degeneracy

4

Universal

44

PYQ 2014

easy

biology ID: neet-ug-

Transformation was discovered by

1

Meselson and Stahl

2

Hershey and Chase

3

Griffith

4

Watson and Crick.

45

PYQ 2014

medium

biology ID: neet-ug-

An analysis of chromosomal DNA using the Southern hybridization technique does not use

1

electrophoresis

2

blotting

3

autoradiography

4

PCR.

46

PYQ 2014

medium

biology ID: neet-ug-

Select the correct option -

1

A

2

B

3

C

4

D

47

PYQ 2014

medium

biology ID: neet-ug-

The force acting on a particle of mass is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to is

1

24 N s

2

20 N s

3

12 N s

4

6 N s

48

PYQ 2016

medium

biology ID: neet-ug-

Which one of the following is the starter codon ?

1

UGA

2

UAA

3

UAG

4

AUG

49

PYQ 2016

medium

biology ID: neet-ug-

DNA-dependent RNA polymerase catalyzes transcription on one strand of the DNA which is called the

1

template strand

2

coding strand

3

alpha strand

4

antistrand

50

PYQ 2016

medium

biology ID: neet-ug-

A molecule that can act as a genetic material must fulfill the traits given below, except

1

it should be able to express itself in the form of ?Mendelian characters'

2

it should be able to generate its replica

3

it should be unstable structurally and chemically

4

it should provide the scope for slow changes that are required for evolution

51

PYQ 2017

medium

biology ID: neet-ug-

If there are 999 bases in an RNA that codes for a protein with 333 amino acids, and the base at position 901 is deleted such that the length of the RNA becomes 998 bases, how many codons will be altered ?

1

11

2

33

3

333

4

1

52

PYQ 2017

medium

biology ID: neet-ug-

Which of the following RNAs should be most abundant in animal cell ?

1

t-RNA

2

m-RNA

3

mi-RNA

4

r-RNA

53

PYQ 2017

medium

biology ID: neet-ug-

During DNA replication, Okazaki fragments are used to elongate:

1

The lagging strand towards replication fork

2

The leading strand away from replication fork

3

The lagging strand away from the replication fork

4

The leading strand towards replication fork

54

PYQ 2018

medium

biology ID: neet-ug-

AGGTATCGCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA?

1

UCCAUAGCGUA

2

AGGUAUCGCAU

3

ACCUAUGCGAU

4

UGGTUTCGCAT

55

PYQ 2018

medium

biology ID: neet-ug-

Select the correct match :

1

G. Mendel - Transformation

2

Ribozyme - Nucleic acid

3

T.H. Morgan - Transduction

4

Recessive parent - Dihybrid cross

56

PYQ 2018

medium

biology ID: neet-ug-

All of the following are part of an operon except

1

a promoter

2

an operator

3

an enhancer

4

structural genes

57

PYQ 2019

medium

biology ID: neet-ug-

Match the following genes of the Lac operon with their respective products: LIST I LIST II A i gene i B-galactosidase B z gene ii Permease C a gene iii Repressor D y gene iv Transacetylase Select the correct option from the following:

1

(a)-(i) (b)-(iii) (c)-(ii) (d)-(iv)

2

(a)-(iii)(b)-(i) (c)-(ii) (d)-(iv)

3

(a)-(iii) (b)-(i) (c)-(iv) (d)-(ii)

4

(a)-(iii) (b)-(iv) (c)-(i) (d)-(ii)

58

PYQ 2019

easy

biology ID: neet-ug-

Expressed Sequence Tags (ESTs) refers to

1

DNA polymorphism

2

Novel DNA sequences

3

Genes expressed as RNA

4

Polypeptide expression

59

PYQ 2019

medium

biology ID: neet-ug-

Which of the following features of genetic code does allow bacteria to produce human insulin by recombinant DNA technology ?

1

Genetic code is nearly universal

2

Genetic code is specific

3

Genetic code is not ambiguous

4

Genetic code is redundant

60

PYQ 2020

medium

biology ID: neet-ug-

Which of the following statements is correct?

1

Adenine pairs with thymine through two H-bonds.

2

Adenine pairs with thymine through one H-bond.

3

Adenine pairs with thymine through three H-bonds.

4

Adenine does not pair with thymine.

61

PYQ 2020

medium

biology ID: neet-ug-

If the distance between two consecutive base pairs is 0.34nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is bp, then the length of the DNA is approximately:

1

2.0 meters

2

2.5 meters

3

2.2 meters

4

2.7 meters

62

PYQ 2021

medium

biology ID: neet-ug-

Which one of the following statements about Histones is wrong

1

Histones carry positive charge in the side chain

2

Histones are organized to form a unit of 8 molecules

3

The pH of histones is slightly acidic

4

Histones are rich in amino acids - Lysine and Arginine

63

PYQ 2021

medium

biology ID: neet-ug-

Identify the correct statement.

1

Split gene arrangement is characteristic of prokaryotes

2

In capping, methyl guanosine triphosphate is added to the 39 end of hnRNA.

3

RNA polymerase binds with Rho factor to terminate the process of transcription in bacteria

4

The coding strand in a transcription unit is copied to an mRNA

64

PYQ 2022

easy

biology ID: neet-ug-

Ten E. coli cells with 15N- dsDNA are incubated in a medium containing 14N nucleotides. After 60 minutes, how many E. coli cells will have DNA totally free from 15N?

1

20 cells

2

40 cells

3

60 cells

4

80 cells

65

PYQ 2022

medium

biology ID: neet-ug-

Transposons can be used during which one of the following?

1

Polymerase chain reaction

2

Gene silencing

3

Autoradiography

4

Gene sequencing

66

PYQ 2022

medium

biology ID: neet-ug-

If a geneticist uses the blind approach for sequencing the whole genome of an organism, followed by assignment of functions to different segment, the methodology adopted by him is called as:

1

Sequence annotation

2

Gene mapping

3

Expressed sequence tags

4

Bioinformatics

67

PYQ 2022

medium

biology ID: neet-ug-

Read the following statements and choose the set of correct statements: Euchromatin is loosely packed chromatin Heterochromatin is transcriptionally active Histone octamer is wrapped by negatively charged DNA in nucleosome Histones are rich in lysine and arginine A typical nucleosome contains 400 bp of DNA helix Choose the correct answer from the options given below:

1

(b), (d), (e) Only

2

(a), (c), (d) Only

3

(b), (e) Only

4

(a), (c), (e) Only

68

PYQ 2023

easy

biology ID: neet-ug-

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 Choose the correct answer from the options given below:

1

A-II, B-III, C-IV, D-I

2

A-III, B-IV, C-I, D-II

3

A-III, B-I, C-IV, D-II

4

A-II, B-I, C-IV, D-III

69

PYQ 2023

easy

biology ID: neet-ug-

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

1

Transcription of tRNA, 5 srRNA and snRNA

2

Transcription of precursor of mRNA

3

Transcription of only snRNAs

4

Transcription of rRNAs (28S, 18S and 5.88)

Official Solution

Correct Option: (1)

In eukaryotic cells, transcription is carried out by three different RNA polymerases, each responsible for synthesizing distinct types of RNA. The role of RNA polymerase III is to transcribe small RNA molecules, including transfer RNA (tRNA), 5S ribosomal RNA (5S rRNA), and certain small nuclear RNAs (snRNA). 1. tRNA Transcription : RNA polymerase III synthesizes tRNAs which play a crucial role in protein synthesis by translating mRNA sequences into amino acids, forming polypeptides. 2. 5S rRNA Transcription : This polymerase also transcribes 5S rRNA, a component of the large subunit of the ribosome. It assists in ribosomal assembly and function during protein synthesis. 3. snRNA Transcription : Some snRNAs, which are involved in RNA splicing and other regulatory processes, are transcribed by RNA polymerase III. RNA Type Role tRNA Translates mRNA into amino acids 5S rRNA Part of the ribosome's large subunit snRNA Involved in RNA processing and regulation The correct role of RNA polymerase III is to transcribe tRNA, 5S rRNA, and snRNA.

70

PYQ 2023

easy

biology ID: neet-ug-

If the length of a DNA molecule is 1.1 metres, what will be the approximate number of base pairs?

1

3.3 \times 10 9 bp

2

6.6 \times 10 9 bp

3

3.3 \times 10 6 bp

4

6.6 \times 10 6 bp