Question 1: Palette 1/182

NEET 2026 MCQ

In the lac operon, the $\boldsymbol{z}$ gene codes for

A

permease

B

transacetylase

C

beta-galactosidase

D

the repressor of lac operon

Question 2: Palette 2/182

NEET 2026 MCQ

Which of the following statements are correct with reference to a transcription unit?

A. A transcription unit in DNA is defined primarily by three regions : promoter, structural gene and terminator.

B. The promoter is said to be located towards the 5'-end of the structural gene.

C. The promoter is a DNA sequence that provides binding site for RNA polymerase.

D. The promoter defines the template and coding strands.

E. The terminator is located towards the $3^{\prime}$-end of the coding strand and it defines the end of the process of transcription.

Choose the correct answer from the options given below:

A

A, B, C and D only

B

A, C, D and E only

C

B, C, D and E only

D

A, B, C, D and E

Question 3: Palette 3/182

NEET 2026 MCQ

Arrange the following steps of DNA fingerprinting in a correct sequence.

A. Isolation of DNA and its digestion by restriction endonucleases.

B. Hybridisation using a labelled VNTR probe.

C. Transferring of separated DNA fragments to synthetic membranes.

D. Detection of hybridised DNA fragments by autoradiography.

E. Separation of DNA fragments by electrophoresis.

Choose the correct answer from the options given below :

A

$\mathrm{A}, \mathrm{B}, \mathrm{D}, \mathrm{C}, \mathrm{E}$

B

$\mathrm{A}, \mathrm{D}, \mathrm{B}, \mathrm{E}, \mathrm{C}$

C

$A, E, C, B, D$

D

$\mathrm{A}, \mathrm{E}, \mathrm{B}, \mathrm{C}, \mathrm{D}$

Question 4: Palette 4/182

NEET 2026 MCQ

Which of the following statements are correct with reference to packaging of DNA helix ?

A. Histones are organized to form a unit of eight molecules called histone octamer.

B. Histones are negatively charged basic proteins.

C. Histones are rich in the basic amino acid residues - lysine and arginine.

D. The positively charged DNA is wrapped around the histone octamer to form nucleosome.

E. The packaging of chromatin at higher levels requires an additional set of proteins called non-histone chromosomal proteins.

Choose the correct answer from the options given below :

A

A, C and E only

B

B, D and E only

C

C, D and E only

D

A, B and D only

Question 5: Palette 5/182

NEET 2026 MCQ

The sixth mutant codon of beta globin gene causing polymerization of Haemoglobin and change in RBC shape is $\_\_\_\_$

A

GUG

B

AUG

C

GAG

D

CAG

Question 6: Palette 6/182

NEET 2026 MCQ

Which of the following statements about lac-operon is correct?

A

Galactose can act as an inducer of lac operon

B

Gene $i$ is constitutively expressed

C

Lactose activates repressor to bind to the operator

D

Genes $i, z, y$ and a share single common promoter

Question 7: Palette 7/182

NEET 2026 MCQ

Which of the following enzymes synthesizes precursor mRNA?

A

DNA polymerase

B

RNA polymerase I

C

RNA polymerase II

D

RNA polymerase III

Question 8: Palette 8/182

NEET 2025 MCQ

Which chromosome in the human genome has the highest number of genes?

A

Chromosome 1

B

Chromosome 10

C

Chromosome X

D

Chromosome Y

Question 9: Palette 9/182

NEET 2025 MCQ

Match List-I with List-II

	List - I		List - II
A	Alfred Hershey and Martha Chase	I	Streptococcus pneumoniae
B	Euchromatin	II	Densely packed and dark-stained
C	Frederick Griffith	III	Loosely packed and light-stained
D	Heterochromatin	IV	DNA as genetic material confirmation

Choose the correct answer from the options given below:

A

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

B

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

C

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

D

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

Question 10: Palette 10/182

NEET 2025 MCQ

Which of the following are the post-transcriptional events in an eukaryotic cell?

A. Transport of pre-mRNA to cytoplasm prior to splicing.

B. Removal of introns and joining of exons.

C. Addition of methyl group at 5' end of hnRNA.

D. Addition of adenine residues at 3' end of hnRNA.

E. Base pairing of two complementary RNAs.

Choose the correct answer from the options given below :

A

B, C, E only

B

C, D, E only

C

A, B, C only

D

B, C, D only

Question 11: Palette 11/182

NEET 2025 MCQ

Given below are two statements:

Statement I: In the RNA world, RNA is considered the first genetic material evolved to carry out essential life processes. RNA acts as a genetic material and also as a catalyst for some important biochemical reactions in living systems. Being reactive, RNA is unstable.

Statement II: DNA evolved from RNA and is a more stable genetic material. Its double helical strands being complementary, resist changes by evolving repairing mechanism.

In the light of the above statements, choose the most appropriate answer from the options given below :

A

Statement I is correct but statement II is incorrect

B

Statement I is incorrect but statement II is correct

C

Both statement I and statement II are correct

D

Both statement I and statement II are incorrect

Question 12: Palette 12/182

NEET 2025 MCQ

Given below are two statements :

Statement 1 : Transfer RNAs and ribosomal RNA do not interact with mRNA.

Statement II : RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.

In the light of the above statements, choose the most appropriate answer from the options given below :

A

Statement I is correct but statement II is incorrect

B

Statement I is incorrect but statement II is correct

C

Both statement I and statement II are correct

D

Both statement I and statement II are incorrect

Question 13: Palette 13/182

NEET 2025 MCQ

Who proposed that the genetic code for amino acids should be made up of three nucleotides?

A

Jacque Monod

B

Franklin Stahl

C

George Gamow

D

Francis Crick

Question 14: Palette 14/182

NEET 2025 MCQ

Which factor is important for termination of transcription?

A

$\rho$ (rho)

B

$\gamma$ (gamma)

C

$\alpha$ (alpha)

D

$\sigma$ (sigma)

Question 15: Palette 15/182

NEET 2024 MCQ

In a chromosome, there is a specific DNA sequence, responsible for initiating replication. It is called as:

A

Recognition sequence

B

Cloning site

C

Restriction site

D

ori site

Question 16: Palette 16/182

NEET 2024 MCQ

Given below are two statements regarding RNA polymerase in prokaryotes.

Statement I : In prokaryotes, RNA polymerase is capable of catalysing the process of elongation during transcription.

Statement II : RNA polymerase associate transiently with ‘Rho’ factor to initiate transcription.

In the light of the above statements, choose the correct answer from the options given below :

A

Statement I is true but Statement II is false

B

Statement I is false but Statement II is true

C

Both Statement I and Statement II are true

D

Both Statement I and Statement II are false

Question 17: Palette 17/182

NEET 2024 MCQ

Given below are two statements:

Statement I: In eukaryotes there are three RNA polymerases in the nucleus in addition to the RNA polymerase found in the organelles.

Statement II: All the three RNA polymerases in eukaryotic nucleus have different roles.

In the light of the above statements, choose the correct answer from the options given below:

A

Statement I is correct but Statement II is incorrect

B

Statement I is incorrect but Statement II is correct

C

Both Statement I and Statement II are correct

D

Both Statement I and Statement II are incorrect

Question 18: Palette 18/182

NEET 2024 MCQ

Given below are two statements :

Statement I: In the lac operon, the z gene codes for beta-galactosidase which is primarily responsible for the hydrolysis of lactose into galactose and glucose.

Statement II: In addition to lactose, glucose or galactose can also induce lac operon.

In the light of the above statements, choose the correct answer from the options given below :

A

Statement I is true but Statement II is false

B

Statement I is false but Statement II is true

C

Both Statement I and Statement II are true

D

Both Statement I and Statement II are false

Question 19: Palette 19/182

NEET 2024 MCQ

Given below are two statements :

Statement I : RNA interference takes place in all Eukaryotic organisms as method of cellular defense.

Statement II : RNAi involves the silencing of a specific mRNA due to a complementary single-stranded RNA molecule that binds and prevents translation of mRNA

In the light of the above statements, choose the correct answer from the options given below.

A

Statement I is true but Statement II is false.

B

Statement I is false but Statement II is true.

C

Both Statement I and Statement II are true.

D

Both Statement I and Statement II are false.

Question 20: Palette 20/182

NEET 2024 MCQ

The lactose present in the growth medium of bacteria is transported to the cell by the action of

A

Beta-galactosidase

B

Acetylase

C

Permease

D

Polymerase

Question 21: Palette 21/182

NEET 2024 MCQ

A transcription unit in DNA is defined primarily by the three regions in DNA and these are with respect to upstream and down stream end;

A

Repressor, Operator gene, Structural gene

B

Structural gene, Transposons, Operator gene

C

Inducer, Repressor, Structural gene

D

Promotor, Structural gene, Terminator

Question 22: Palette 22/182

NEET 2024 MCQ

Which of the following statement is correct regarding the process of replication in E.coli?

A

'The DNA dependent DNA polymerase catalyses polymerization in one direction that is $3^{\prime} \rightarrow 5$'

B

The DNA dependent RNA polymerase catalyses polymerization in one direction, that is $5^{\prime} \rightarrow 3^{\prime}$

C

The DNA dependent DNA polymerase catalyses polymerization in 5' $\rightarrow$ 3' as well as $3^{\prime} \rightarrow 5^{\prime}$ direction

D

The DNA dependent DNA polymerase catalyses polymerization in 5' $\rightarrow$ 3' direction

Question 23: Palette 23/182

NEET 2024 MCQ

Match List I with List II

	List - I		List - II
A.	Frederick Griffith	I.	Genetic code
B.	Francois Jacob & Jacque Monod	II.	Semi-conservative mode of DNA replication
C.	Har Gobind Khorana	III.	Tranformation
D.	Meselson & Stahl	IV.	Lac operon

Choose the correct answer from the options given below:

A

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

B

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

C

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

D

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

Question 24: Palette 24/182

NEET 2024 MCQ

Match List I with List II :

	List - I		List - II
A.	Down's syndrome	I.	11$^\mathrm{th}$ chromosome
B.	$\alpha$-thalassemia	II.	'X' chromosome
C.	$\beta$-thalassemia	III.	21$^\mathrm{st}$ chromosome
D.	Klinefelter's syndrome	IV.	16$^\mathrm{th}$ chromosome

Choose the correct answer from the options given below :

A

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

B

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

C

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

D

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

Question 25: Palette 25/182

NEET 2024 MCQ

Which one is the correct product of DNA dependent RNA polymerase to the given template?

3'TACATGGCAAATATCCATTCA5'

A

5'AUGUACCGUUUAUAGGUAAGU3'

B

5'AUGUAAAGUUUAUAGGUAAGU3'

C

5'AUGUACCGUUUAUAGGGAAGU3'

D

5'ATGTACCGTTTATAGGTAAGT3'

Question 26: Palette 26/182

NEET 2024 MCQ

Match List I with List II:

	List - I		List - II
A.	RNA polymerase III	I.	snRNPs
B.	Termination of transcription	II.	Promotor
C.	Splicing of Exons	III.	Rho factor
D.	TATA box	IV.	SnRNAs, tRNA

Choose the correct answer from the options given below :

A

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

B

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

C

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

D

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

Question 27: Palette 27/182

NEET 2023 MCQ

The last chromosome sequenced in Human Genome Project was:

A

Chromosome 6

B

Chromosome 1

C

Chromosome 22

D

Chromosome 14

Question 28: Palette 28/182

NEET 2023 MCQ

Name the component that binds to the operator region of an operon and prevents RNA polymerase from transcribing the operon.

A

Promotor

B

Regulator protein

C

Repressor protein

D

Inducer

Question 29: Palette 29/182

NEET 2023 MCQ

Given below are two statements :

Statement I : The process of copying genetic information from one strand of the DNA into RNA is termed as transcription.

Statement II : A transcription unit in DNA is defined primarily by the three regions in the DNA i.e., a promotor, the structural gene and a terminator.

In the light of the above statements, choose the correct answer from the options given below :

A

Statement I is true but Statement II is false

B

Statement I is false but Statement II is true

C

Both Statement I and Statement II are true

D

Both Statement I and Statement II are false

Question 30: Palette 30/182

NEET 2023 MCQ

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

A

james D. Watson and F.H. C. Crick

B

A. D Hershey and M.J. Chase

C

F. Griffith

D

O.T. Avery, C.M. MacLeod and M. McCarty

Question 31: Palette 31/182

NEET 2023 MCQ

Given below are two statements :

Statement I : RNA being unstable, mutate at a faster rate.

Statement II : RNA can directly code for synthesis of proteins hence can easily express the characters.

In the light of the above statements, choose the correct answer from the options given below :

A

Statement I is correct but Statement II is false

B

Statement I is incorrect but Statement II is true

C

Both Statement I and Statement II are true

D

Both Statement I and Statement II are false

Question 32: Palette 32/182

NEET 2023 MCQ

Select the correct statements about sickle cell anaemia.

(A) There is a change in gene for beta globin.

(B) In the beta globin, there is valine in the place of Lysine.

(C) It is an example of point mutation.

(D) In the normal gene U is replaced by A.

Choose the correct answer from the options given below :

A

(B), (C) and (D) only

B

(B) and (D) only

C

(A), (B) and (D) only

D

(A) and (C) only

Question 33: Palette 33/182

NEET 2023 MCQ

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

A

Sucrose

B

Lactose

C

Glucose

D

Galactose

Question 34: Palette 34/182

NEET 2023 MCQ

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 most appropriate answer from the options given below :

A

(D) and (E) only

B

(A) and (B) only

C

(A) and (C) only

D

(B) and (D) only

Question 35: Palette 35/182

NEET 2023 MCQ

The salient features of genetic code are :

(A) The code is palindromic

(B) UGA act as initiator codon

(C) The code is unambiguous and specific

(D) The code is nearly universal

Choose the most appropriate answer from the options given below :

A

(A) and (D) only

B

(B) and (C) only

C

(A) and (B) only

D

(C) and (D) only

Question 36: Palette 36/182

NEET 2023 MCQ

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

A

Alfred Hershey and Martha Chase

B

Avery, Macleoid and McCarthy

C

Wilkins and Franklin

D

Frederick Griffith

Question 37: Palette 37/182

NEET 2023 MCQ

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

A

Transcription of tRNA, 5S rRNA and snRNA

B

Transcription of precursor of mRNA

C

Transcription of only snRNAs

D

Transcription of rRNAs (28S, 18S and 5.8S)

Question 38: Palette 38/182

NEET 2023 MCQ

Expressed Sequence Tags (ESTs) refers to

A

All genes that are expressed as proteins.

B

All genes whether expressed or unexpressed.

C

Certain important expressed genes.

D

All genes that are expressed as RNA.

Question 39: Palette 39/182

NEET 2023 MCQ

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

A

Bright blue colour

B

Bright yellow colour

C

Bright orange colour

D

Bright red colour

Question 40: Palette 40/182

NEET 2023 MCQ

Match List I with List II.

	List I		List II
(A)	Gene 'a'	(I)	$\beta$-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 :

A

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

B

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

C

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

D

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

Question 41: Palette 41/182

NEET 2023 MCQ

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.

In the light of the above statements, choose the correct answer from the options given below:

A

Both Statement I and Statement II are false.

B

Statement I is correct but Statement II is false.

C

Statement I is incorrect but Statement II is true.

D

Both Statement I and Statement II are true.

Question 42: Palette 42/182

NEET 2023 MCQ

Which one of the following is the sequence on corresponding coding strand, if the sequence on mRNA formed is as follows 5’AUCGAUCGAUCGAUCGAUCGAUCG AUCG 3’?

A

3’ UAGCUAGCUAGCUAGCUAGCUAGCUAGC 5’

B

5’ ATCGATCGATCGATCGATCGATCGATCG 3’

C

3’ ATCGATCGATCGATCGATCGATCGATCG 5’

D

5’ UAGCUAGCUAGCUAGCUAGCUAGCUAGC 3’

Question 43: Palette 43/182

NEET 2022 MCQ

In lac operon, z gene codes for

A

Transacetylase

B

$\beta$-galactosidase

C

Permease

D

Repressor

Question 44: Palette 44/182

NEET 2022 MCQ

Given below are two statements

Statement I : DNA polymerases catalyse polymerisation only in one direction, that is 5' → 3'.

Statement II : During replication of DNA, on one strand the replication is continuous while on other strand it is discontinuous.

In the light of the above statements, choose the correct answer from the options given below:

A

Statement I is incorrect but Statement II is correct

B

Both Statement I and Statement II are correct

C

Both Statement I and Statement II are incorrect

D

Statement I is correct but Statement II is incorrect

Question 45: Palette 45/182

NEET 2022 MCQ

Match List - I with List - II.

	List - I		List - II
(a)	In Iac operon i gene codes for	(i)	transacetylase
(b)	In Iac operon z gene codes for	(ii)	permease
(c)	In Iac operon y gene codes for	(iii)	$\beta$-galactosidase
(d)	In Iac operon a gene codes for	(iv)	Repressor

Choose the correct answer from the options given below

A

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

B

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

C

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

D

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

Question 46: Palette 46/182

NEET 2022 MCQ

Match List-I with List-II:

	List - I		List - II
(a)	Bacteriophage $\phi$ $\times$ 174	(i)	48502 base pairs
(b)	Bacteriophage lambda	(ii)	5386 nucleotides
(c)	Escherichia coli	(iii)	3.3 $\times$ 10$^9$ base pairs
(d)	Haploid content of human DNA	(iv)	4.6 $\times$ 10$^6$ base pairs

Choose the correct answer from the options given below:

A

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

B

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

C

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

D

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

Question 47: Palette 47/182

NEET 2022 MCQ

Against the codon 5' UAC 3', what would be the sequence of anticodon on tRNA?

A

5' GUA 3'

B

5' AUG 3'

C

5' ATG 3'

D

5' GTA 3'

Question 48: Palette 48/182

NEET 2022 MCQ

If A and C make 30% and 20% of DNA, respectively, what will be the percentage composition of T and G?

A

T : 20%, G : 20%

B

T : 20%, G : 30%

C

T : 30%, G : 20%

D

T : 30%, G : 30%

Question 49: Palette 49/182

NEET 2022 MCQ

The process of translation of mRNA to proteins begins as soon as:

A

The small subunit of ribosome encounters mRNA

B

The larger subunit of ribosome encounters mRNA

C

Both the subunits join together to bind with mRNA

D

The tRNA is activated and the larger subunit of ribosome encounters mRNA

Question 50: Palette 50/182

NEET 2022 MCQ

DNA polymorphism forms the basis of:

A

Genetic mapping

B

DNA finger printing

C

Both genetic mapping and DNA finger printing

D

Translation

Question 51: Palette 51/182

NEET 2022 MCQ

Read the following statements and choose the set of correct statements:

(a) Euchromatin is loosely packed chromatin

(b) Heterochromatin is transcriptionally active

(c) Histone octamer is wrapped by negatively charged DNA in nucleosome

(d) Histones are rich in lysine and arginine

(e) A typical nucleosome contains 400 bp of DNA helix

Choose the correct answer from the options given below :

A

(b), (d), (e) only

B

(a), (c), (d) only

C

(b), (e) only

D

(a), (c), (e) only

Question 52: Palette 52/182

NEET 2022 MCQ

Transposons can be used during which one of the following?

A

Polymerase Chain Reaction

B

Gene Silencing

C

Autoradiography

D

Gene sequencing

Question 53: Palette 53/182

NEET 2022 MCQ

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

A

Sequence annotation

B

Gene mapping

C

Expressed sequence tags

D

Bioinformatics

Question 54: Palette 54/182

NEET 2022 MCQ

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

A

3.3 $\times$ bp 10⁹

B

6.6 $\times$ bp 10⁹

C

3.3 $\times$ bp 10⁶

D

6.6 $\times$ bp 10⁶

Question 55: Palette 55/182

NEET 2022 MCQ

In an E. Coli strain i gene gets mutated and its product can not bind the inducer molecule. If growth medium is provided with lactose, what will be the outcome?

A

Only z gene will get transcribed

B

z, y, a genes will be transcribed

C

z, y, a genes will not be translated

D

RNA polymerase will bind the promoter region

Question 56: Palette 56/182

NEET 2022 MCQ

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

A

20 cells

B

40 cells

C

60 cells

D

80 cells

Question 57: Palette 57/182

NEET 2021 MCQ

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

A

Bright blue bands

B

Yellow bands

C

Bright orange bands

D

Dark red bands

Question 58: Palette 58/182

NEET 2021 MCQ

Complete the flow chart on central dogma.

A

(a) - Transduction; (b) - Translation; (c) - Replication; (d) - Protein

B

(a) - Replication; (b) - Transcription; (c) - Transduction; (d) - Protein

C

(a) - Translation; (b) - Replication; (c) - Transcription; (d) - Transduction

D

(a) - Replication; (b) - Transcription; (c) - Translation; (d) - Protein

Question 59: Palette 59/182

NEET 2021 MCQ

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

A

Transcribes only snRNAs

B

Transcribes rRNAs (28S, 18S and 5.8S)

C

Transcribes tRNA, 5s rRNA and snRNA

D

Transcribes precursor of mRNA

Question 60: Palette 60/182

NEET 2021 MCQ

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

A

Polymorphic DNA

B

Satellite DNA

C

Repetitive DNA

D

Single nucleotides

Question 61: Palette 61/182

NEET 2021 MCQ

Identify the correct statement.

A

Split gene arrangement is characteristic of prokaryotes

B

In capping, methyl guanosine triphosphate is added to the 3' end of hnRNA

C

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

D

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

Question 62: Palette 62/182

NEET 2021 MCQ

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

A

T : 20 ; G : 25 ; C : 25

B

T : 20 ; G : 30 ; C : 20

C

T : 20 ; G : 20 ; C : 30

D

T : 30 ; G : 20 ; C : 20

Question 63: Palette 63/182

NEET 2021 MCQ

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

A

siRNA

B

mRNA

C

tRNA

D

rRNA

Question 64: Palette 64/182

NEET 2021 MCQ

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

A

DNase

B

DNA dependent DNA polymerase

C

DNA dependent RNA polymerase

D

DNA Ligase

Question 65: Palette 65/182

NEET 2021 MCQ

Which one of the following statements about histones is wrong?

A

Histones carry positive charge in the side chain

B

Histones are organized to form a unit of 8 molecules

C

The pH of histones is slightly acidic

D

Histones are rich in amino acids - Lysine and Arginine

Question 66: Palette 66/182

NEET 2021 MCQ

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.

A

Statement I is incorrect but Statement II is true

B

Both Statement I and Statement II are true

C

Both Statement I and Statement II are false

D

Statement I is correct but Statement II is false

Question 67: Palette 67/182

NEET 2020 MCQ

If the distance between two consecutive base pairs is 0.34 nm and the total number of base pairs of a DNA double helix in a typical mammalian cell is 6.6 × 109 bp, then the length of the DNA is approximately

A

2.7 meters

B

2.0 meters

C

2.5 meters

D

2.2 meters

Question 68: Palette 68/182

NEET 2020 MCQ

Which of the following statements is correct?

A

Adenine does not pair with thymine

B

Adenine pairs with thymine through one H-bond

C

Adenine pairs with thymine through two H-bonds

D

Adenine pairs with thymine through three H-bonds

Question 69: Palette 69/182

NEET 2020 MCQ

The first phase of translation is

A

Recognition of an anti-codon

B

Recognition of DNA molecule

C

Binding of mRNA to ribosome

D

Aminoacylation of tRNA

Question 70: Palette 70/182

NEET 2020 MCQ

Name the enzyme that facilitates opening of DNA helix during transcription.

A

DNA polymerase

B

RNA polymerase

C

DNA helicase

D

DNA ligase

Question 71: Palette 71/182

NEET 2019 MCQ

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

A

Genetic code is nearly universal

B

Genetic code is specific

C

Genetic code is not ambiguous

D

Genetic code is redundant

Question 72: Palette 72/182

NEET 2019 MCQ

The shorter and longer arms of a submetacentric chromosome are referred to as:

A

q-arm and p-arm respectively

B

m-arm and n-arm respectively

C

s-arm and l-arm respectively

D

p-arm and q-arm respectively

Question 73: Palette 73/182

NEET 2019 MCQ

Match the following genes of the Lac operon with their respective produces :

(a) i gene	(i) $\beta $-galactosidase
(b) z gene	(ii) Permease
(c) a gene	(iii) Repressor
(d) y gene	(iv) Transacetylase

Select the correct option.

A

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

B

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

C

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

D

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

Question 74: Palette 74/182

NEET 2019 MCQ

Expressed Sequence Tags (ESTs) refers to :

A

DNA polymorphism

B

Novel DNA sequences

C

Genes expressed as RNA

D

Polypeptide expression

Question 75: Palette 75/182

NEET 2019 MCQ

Purines found both in DNA and RNA are:

A

Guanine and cytosine

B

Cytosine and thymine

C

Adenine and thymine

D

Adenine and guanine

Question 76: Palette 76/182

NEET 2019 MCQ

Under which of the following conditions will there be no change in the reading frame of following mRNA?

5' AACAGCGGUGCUAUU 3'

A

Insertion of A and G at 4^th and 5^th positions respectively

B

Deletion of GGU from 7^th, 8^th and 9^th positions

C

Insertion of G at 5^th positions

D

Deletion of G from 5^th positions

Question 77: Palette 77/182

NEET 2018 MCQ

Select the correct statement :

A

Franklin Stahl coined the term ‘‘linkage’’.

B

Punnett square was developed by a British scientist.

C

Spliceosomes take part in translation.

D

Transduction was discovered by S. Altman

Question 78: Palette 78/182

NEET 2018 MCQ

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

A

AGGUAUCGCAU

B

UGGTUTCGCAT

C

ACCUAUGCGAU

D

UCCAUAGCGUA

Question 79: Palette 79/182

NEET 2018 MCQ

All of the following are part of an operon except

A

an operator

B

structural genes

C

an enhancer

D

a promoter

Question 80: Palette 80/182

NEET 2018 MCQ

The experimental proof for semi-conservative replication of DNA was first shown in a

A

fungus

B

bacterium

C

plant

D

virus.

Question 81: Palette 81/182

NEET 2018 MCQ

Select the correct match :

A

Alec Jeffreys - Streptococcus pneumoniae

B

Alfred Hershey and - TMV Martha Chase

C

Matthew Meselson - Pisum sativum and F. Stahl

D

Francois Jacob and - Lac operon Jacques Monod

Question 82: Palette 82/182

NEET 2018 MCQ

Select the correct match :

A

Ribozyme - Nucleic acid

B

F₂ $ \times $ Recessive parent - Dihybrid cross

C

T.H. Morgan - Transduction

D

G. Mendel - Transformation

Question 83: Palette 83/182

NEET 2018 MCQ

Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as

A

polysome

B

polyhedral bodies

C

plastidome

D

nucleosome

Question 84: Palette 84/182

NEET 2017 MCQ

During DNA replication, Okazaki fragments are used to elongate

A

The leading strand away from replication fork

B

The lagging strand towards replication fork

C

The lagging strand away from the replication fork

D

The leading strand towards replication fork

Question 85: Palette 85/182

NEET 2017 MCQ

Spliceosomes are not found in cells of :

A

Bacteria

B

Plants

C

Animals

D

Fungi

Question 86: Palette 86/182

NEET 2017 MCQ

The association of histone H₁ with a nucleosome indicates :

A

DNA replication is occurring

B

Transcription is occurring

C

The DNA is condensed into a Chromatin Fibre

D

The DNA double helix is exposed

Question 87: Palette 87/182

NEET 2017 MCQ

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 ?

A

1

B

11

C

333

D

33

Question 88: Palette 88/182

NEET 2017 MCQ

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

A

m-RNA

B

mi-RNA

C

r-RNA

D

t-RNA

Question 89: Palette 89/182

NEET 2017 MCQ

The final proof for DNA as the genetic material came from the experiments of

A

Griffith

B

Hargobind Khorana

C

Avery, Mcleod and McCarty

D

Hershey and chase

Question 90: Palette 90/182

NEET 2016 MCQ

The equivalent of a structural gene is -

A

cistron

B

recon

C

muton

D

operon

Question 91: Palette 91/182

NEET 2016 MCQ

Taylor conducted the experiments to prove semiconservative mode of chromosome replication on

A

Vicia faba

B

Drosophila melanogaster

C

Vinca rosea

D

E. coli

Question 92: Palette 92/182

NEET 2016 MCQ

Which of the following rRNAs acts as structural RNA as well as ribozyme in bacteria ?

A

5.8 S rRNA

B

23 S rRNA

C

18 S rRNA

D

5 S rRNA

Question 93: Palette 93/182

NEET 2016 MCQ

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

A

it should be able to express itself in the form of ‘Mendelian characters’

B

it should be unstable structurally and chemically

C

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

D

it should be able to generate its replica

Question 94: Palette 94/182

NEET 2016 MCQ

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

A

coding strand

B

antistrand

C

template strand

D

alpha strand

Question 95: Palette 95/182

NEET 2016 MCQ

Which one of the following is the starter codon ?

A

AUG

B

UAG

C

UAA

D

UGA

Question 96: Palette 96/182

NEET 2016 MCQ

Which of the following is required as inducer(s) for the expression of Lac operon?

A

lactose

B

lactose and galactose

C

glucose

D

galactose

Question 97: Palette 97/182

NEET 2016 MCQ

A complex of ribosomes attached to a single strand of RNA is known as :

A

Polypeptide

B

Okazaki fragment

C

Polysome

D

Polymer

Question 98: Palette 98/182

NEET 2015 MCQ

Satellite DNA is important because it :

A

Shows high degree of polymorphism in population and also the same degree of polymorphism in an individual, which is heritable from parents to children.

B

does not code for proteins and is same in all members of the population.

C

codes for proteins needed in cell cycle.

D

codes for proteins needed in cell cycle.

Question 99: Palette 99/182

NEET 2015 MCQ

Balbiani rings are sites of :

A

Polysaccharide synthesis

B

Lipid synthesis

C

RNA and protein synthesis

D

Nucleotide synthesis

Question 100: Palette 100/182

NEET 2015 MCQ

Which one of the following is not applicable to RNA?

A

Complementary base pairing

B

5' phosphoryl and 3' hydroxyl ends

C

Heterocyclic nitrogenous bases

D

Chargaff's rule

Question 101: Palette 101/182

NEET 2015 MCQ

Identify the correct order of organisation of genetic material from largest to smallest :

A

Chromosome, genome, nucleotide, gene

B

Genome, chromosome, nucleotide, gene

C

Genome, chromosome, gene, nucleotide

D

Chromosome, gene, genome, nucleotide

Question 102: Palette 102/182

NEET 2015 MCQ

Gene regulation governing lactose operon of E.coli that involves the lac I gene product is

A

negative and inducible because repressor protein prevents transcription.

B

positive and inducible because it can be induced by lactose

C

negative and repressible because repressor protein prevents transcription

D

feedback inhibition because excess of $\beta $-galactosidase can switch off transcription

Question 103: Palette 103/182

NEET 2015 MCQ

In sea urchin DNA, which is double stranded, 17% of the bases were shown to be cytosine, The percentages of the other three bases expected to be present in this DNA are

A

G 17%, A 16.5%, T 32.5%

B

G 17%, A 33%, T 33%

C

G 8.5%, A 50%, T 24.5%

D

G 34%, A 24.5%, T 24.5%

Question 104: Palette 104/182

NEET 2014 MCQ

Transformation was discovered by :

A

Griffith

B

Watson and Crick

C

Hershey and Chase

D

Meselson and Stahl

Question 105: Palette 105/182

NEET 2014 MCQ

Select the correct option ;

A

Direction of RNA synthesis 3’−5’, Direction of reading of the template DNA strand 5’−3’

B

Direction of RNA synthesis 5’−3’, Direction of reading of the template DNA strand 5’−3’

C

Direction of RNA synthesis 5’−3’, Direction of reading of the template DNA strand 3’−5’

D

Direction of RNA synthesis 3’−5’, Direction of reading of the template DNA strand 3’−5’

Question 106: Palette 106/182

NEET 2014 MSQ

Which one of the following is wrongly matched?

A

Transcription − Writing information from DNA to t−RNA

B

Operon − Structural genes, operator and promoter

C

Repressor protein − Binds to operator to stop enzyme synthesis

D

Translation − Using information in m−RNA to make protein.

Question 107: Palette 107/182

NEET 2013 MCQ

One of the most frequently used techniques in DNA fingerprinting is :-

A

SSCP

B

SCAR

C

VNTR

D

AFLP

Question 108: Palette 108/182

NEET 2013 MCQ

The figure gives an important concept in the genetic implication of DNA . Fill the blanks A, B and C.

A

A - Erwin Chargaff
B - translation
C - replication

B

A - Maurice Wilkins
B - transcription
C - translation

C

A - Francis Crick
B - translation
C - transcription

D

A - James Watson
B - replication
C - extension

Question 109: Palette 109/182

NEET 2013 MCQ

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

A

Ambiguous

B

Universal

C

Degeneracy

D

Non-overlapping

Question 110: Palette 110/182

NEET 2013 MCQ

Satellite RNA are present in some :

A

Prions

B

Bacteriophages

C

Plant viruses

D

Viroids

Question 111: Palette 111/182

NEET 2013 MCQ

Genes of interest can be selected from a genomic library by using :

A

Restriction enzymes

B

Gene targets

C

Cloning vectors

D

DNA probes

Question 112: Palette 112/182

NEET 2013 MCQ

In an inducible operon, the genes are :

A

usually expressed unless a signal turns them "off"

B

always expressed

C

never expressed

D

usually not expressed unless a signal turns them "on"

Question 113: Palette 113/182

NEET 2013 MCQ

Which of the following statements is not true of two genes that show 50% recombination frequency ?

A

The genes are tightly linked

B

The genes show independent assortment

C

If the genes are present on the same chromosome, they undergo more than one crossovers in every meiosis.

D

The genes may be on different chromosomes

Question 114: Palette 114/182

NEET 2013 MCQ

The diagram shows an important concept in the genetic implication of DNA. Fill in the blanks A to C.

A

A-translation B-extension C-Rosalind Franklin

B

A-translation B-transcription C-Erevin Chargaff

C

A-transcription B-translation C-Francis Crick

D

A-transcription B-replication C-James Watson

Question 115: Palette 115/182

NEET 2013 MCQ

Which enzyme will be produced in a cell in which there is a non-sense mutation in the lac Y gene ?

A

Transacetylase

B

Lactose permease and transacetylase

C

Lactose permease

D

$\beta $-galactosidase

Question 116: Palette 116/182

NEET 2012 MCQ

Read the following four statements (A-D) :
(A) In transcription, adenosine pairs with uracil
(B) Regulation of lac operon by repressor is referred to as positive regulation
(C) The human genome has approximately 50,000 genes
(D) Haemophilia is a sex-linked recessive disease
How many of the above statements are right ?

A

Four

B

Two

C

Three

D

One

Question 117: Palette 117/182

NEET 2012 MCQ

Removal of introns and joining of exons in a defined order during transcription is called

A

Looping

B

Inducing

C

Slicing

D

Splicing

Question 118: Palette 118/182

NEET 2012 MCQ

Which one of the following is not a part of a transcription unit in DNA ?

A

The structural gene

B

the inducer

C

A terminator

D

A promoter

Question 119: Palette 119/182

NEET 2012 MCQ

Ribosomal RNA is actively synthesized in

A

Nucleolus

B

Ribosomes

C

Lysosomes

D

Nucleoplasm

Question 120: Palette 120/182

NEET 2012 MCQ

If one strand of DNA has the nitrogenous base sequence as ATCTG, what would be the complementary RNA stand sequence

A

ATCGU

B

UAGAC

C

AACTG

D

TTAGU

Question 121: Palette 121/182

NEET 2012 MCQ

Removal of RNA polymerase -III from nucleoplasm will affect the synthesis of

A

tRNA

B

hnRNA

C

rRNA

D

mRNA

Question 122: Palette 122/182

NEET 2011 MCQ

The unequivocal proof of DNA as the genetic material came from the studies on a :

A

Viroid

B

Bacterium

C

Fungus

D

Bacterial virus

Question 123: Palette 123/182

NEET 2011 MCQ

What are those structures that appear as 'beads-on-string' in the chromosomes when viewed under electron microscope ?

A

Nucleosomes

B

Genes

C

Nucleotides

D

Base pairs

Question 124: Palette 124/182

NEET 2010 MCQ

The 3'-5' phosphodiester linkages inside a polynucleotide chain serve to join -

A

One nucleotide with another nucleotide

B

One nitrogenous base with pentose sugar

C

One nucleoside with another nucleoside

D

One DNA strand with the other DNA strand

Question 125: Palette 125/182

NEET 2010 MCQ

In eukaryotic cell transcription, RNA splicing and RNA capping take place inside the -

A

Dictyosomes

B

Ribosomes

C

Nucleus

D

ER

Question 126: Palette 126/182

NEET 2010 MCQ

Which one of the follwoing statements about the particular entity is true ?

A

Nucleosome is formed of nucleotides

B

Centromere is found in animals cells, which produces aster during cell division

C

The gene for producing insulin is present in every body cell

D

DNA consists of a core of eight histones

Question 127: Palette 127/182

NEET 2010 MCQ

The lac Operon consists of -

A

Three regulatory genes and three structure genes

B

Four regulatory genes only

C

Two regulatory genes and two structural genes

D

One regulatory gene and three structural genes

Question 128: Palette 128/182

NEET 2010 MCQ

Select the two correct statements out of the four (a-d) statements given below about lac operon.
(a) Glucose or galactose may bind with the repressor and inactivate it
(b) In the absence of lactose the repressor binds with the operator region
(c) The z-gene codes for permease
(d) This was elucidated by Francois Jacob and Jacque Monod
The correct statements are :

A

(b) and (d)

B

(a) and (b)

C

(b) and (c)

D

(a) and (c)

Question 129: Palette 129/182

NEET 2010 MCQ

Which one of the following does not follow the central dogma of molecular biology ?

A

Mucor

B

HIV

C

Chlamydomonas

D

Pea

Question 130: Palette 130/182

NEET 2010 MCQ

The one aspect which is not a salient feature of genetic code, is its being –

A

Specific

B

Degenerate

C

Ambiguous

D

Universal

Question 131: Palette 131/182

NEET 2010 MCQ

Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzyme?

A

5' _____ CG TTCG ______ 3'
3' ______ATGGTA ______5'

B

5'______GAATTC ______3'
3'______CTTAAG______5'

C

5'______CACGTA______3'
3'______CTCAGT______5'

D

5'______GATATG ______3'
3'______CTACTA ______5'

Question 132: Palette 132/182

NEET 2009 MCQ

Whose experiments cracked the DNA and discovered unequivocally that a genetic code is a "triplet" ?

A

Nirenberg and Mathaei

B

Morgan and Sturtevant

C

Hershey and Chase

D

Beadle and Tatum

Question 133: Palette 133/182

NEET 2009 MCQ

Removal of introns and joining the exons in a defined order in a transcription unit is called :

A

Transformation

B

Capping

C

Splicing

D

Tailing

Question 134: Palette 134/182

NEET 2009 MCQ

What is not true for genetic code?

A

It is nearly universal

B

A codon in mRNA is read in a noncontiguous fashion

C

It is degenerate

D

It is unambiguous

Question 135: Palette 135/182

NEET 2009 MCQ

Semi-conservative replication of DNA was first demonstrated in :

A

Drosophila melanogaster

B

Streptococcus pneumoniae

C

Salmonella typhimurium

D

Escherichia coli

Question 136: Palette 136/182

NEET 2008 MCQ

Which one of the following pairs of nitrogenous bases of nucleic acids, is wrongly matched with the category mentioned against it?

A

Thymine, Uracil — Pyrimidines

B

Guanine, Adenine — Purines

C

Uracil, Cytosine — Pyrimidines

D

Adenine, Thymine — Purines

Question 137: Palette 137/182

NEET 2008 MCQ

Which one of the following pairs of codons is correctly matched with their function or the signal for the particular amino acid ?

A

UUA, UCA — Leucine

B

AUG, ACG — Start/Methionine

C

UAG, UGA — Stop

D

GUU, GCU — Alanine

Question 138: Palette 138/182

NEET 2008 MCQ

Polysome is formed by

A

several ribosomes attached to a single mRNA

B

many ribosomes attached to a strand of endoplasmic reticulum

C

a ribosome with several subunits

D

ribosomes attached to each other in a linear arrangement

Question 139: Palette 139/182

NEET 2008 MCQ

In the DNA molecule:

A

the total amount of purine nucleotides and pyrimidine nucleotides is not always equal

B

there are two strands which run antiparallel one in 5'→ 3' direction and other in 3'→ 5'

C

there are two strands which run parallel in the 5'→ 3' direction

D

the proportion of adenine in relation to thymine varies with the organism

Question 140: Palette 140/182

NEET 2006 MCQ

Which antibiotic inhibits interaction between tRNA and mRNA during bacterial protein synthesis ?

A

Neomycin

B

Erythromycin

C

Tetracycline

D

Streptomycin

Question 141: Palette 141/182

NEET 2006 MCQ

Antiparallel strands of a DNA molecule means that-

A

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

B

One strand turns anti-clockwise

C

One strand turns clockwise

D

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

Question 142: Palette 142/182

NEET 2006 MCQ

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

A

cDNA

B

mRNA

C

tRNA

D

rRNA

Question 143: Palette 143/182

NEET 2006 MCQ

One gene-one enzyme hypothesis was postulated by -

A

A.Garrod

B

Hershey and Chase

C

Beadle and Tatum

D

R. Franklin

Question 144: Palette 144/182

NEET 2006 MCQ

One turn of the helix in a B-form DNA is approximately -

A

20 nm

B

3.4 nm

C

2 nm

D

0.34 nm

Question 145: Palette 145/182

NEET 2005 MCQ

Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain ?

A

protease

B

Endonuclease

C

Lipase

D

Exonuclease

Question 146: Palette 146/182

NEET 2005 MCQ

Telomerase is an enzyme which is a -

A

RNA

B

Repetitive DNA

C

Simple protein

D

Ribonucleoprotein

Question 147: Palette 147/182

NEET 2005 MCQ

Using imprints from a plate with complete medium and carrying bacterial colonies, you can select streptomycin resistant mutants and prove that such mutations do not originates as adaptation. These imprints need to be used -

A

On plates with minimal medium

B

Only on plates with streptomycin

C

Only on plates without streptomycin

D

On plates with and without streptomycin

Question 148: Palette 148/182

NEET 2005 MCQ

Which one of the following makes use of RNA as a template to synthesize DNA -

A

Reverse transcriptase

B

DNA dependant RNA polymerase

C

RNA polymerase

D

DNA polymerase

Question 149: Palette 149/182

NEET 2005 MCQ

During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at the point. What is the sequence called ?

A

TATA box

B

GGTT box

C

CAAT box

D

AAAT box

Question 150: Palette 150/182

NEET 2005 MCQ

Protein synthesis in an animal cell occurs -

A

On ribosomes present in the nucleolus as well as in cytoplasm

B

On ribosomes presents in cytoplasm as well as in mitochondria

C

Only on the ribosomes present in cytosol

D

Only on ribosomes attached to the nuclear envelope and endoplasmic reticulum

Question 151: Palette 151/182

NEET 2005 MCQ

E. coli cells with a mustard z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because -

A

They cannot transport lactose from the medium into the cell

B

They cannot synthesize functional beta galactosidase

C

In the presence of glucose, E. coli cells do not utilize lactose

D

The lac operon is constitutively active in these cells

Question 152: Palette 152/182

NEET 2004 MCQ

In a mutational event, when adenine is replaced by guanine, it is a case of -

A

Frameshift mutation

B

Transition

C

Transversion

D

Transcription

Question 153: Palette 153/182

NEET 2004 MCQ

Which form of RNA has a structure resembling clover leaf ?

A

r-RNA

B

m-RNA

C

t-RNA

D

hn-RNA

Question 154: Palette 154/182

NEET 2004 MCQ

The following ratio is generally constant for a given species :-

A

A + C / T + G

B

G + C / A+ T

C

A + G / C +T

D

T + C / G + A

Question 155: Palette 155/182

NEET 2004 MCQ

After a mutation at a genetic locus the character of an organism changes due to the change in :-

A

Protein synthesis pattern

B

RNA transcription pattern

C

DNA replication

D

Protein structure

Question 156: Palette 156/182

NEET 2004 MCQ

During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG, then the nucleotide sequence in the mRNA would be -

A

UAUGC

B

TCTGG

C

UATGC

D

TATGC

Question 157: Palette 157/182

NEET 2003 MCQ

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

A

Association of 30S mRNA with formy-lmet-tRNA

B

Formation of formyl-met-tRNA

C

Association of 50S subunit of ribosome with initiation complex

D

Binding of 30S subunit of ribosome with mRNA

Question 158: Palette 158/182

NEET 2003 MCQ

In the genetic code dictionary, how many codons are used to code for all the 20 essential amino acids : -

A

64

B

20

C

60

D

61

Question 159: Palette 159/182

NEET 2003 MCQ

Degeneration of a genetic code is attributed to the : -

A

Second member of a codon

B

Third member of a codon

C

First member of a codon

D

Entire codon

Question 160: Palette 160/182

NEET 2003 MCQ

What does "lac" refer to in what we call the lac operon ?

A

The number 1,00,000

B

Lac insect

C

Lactase

D

Lactose

Question 161: Palette 161/182

NEET 2003 MCQ

Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as 'start' or 'stop' codon ?

A

UUU – Stop

B

UAC – Tyrosine

C

UGU – Leucine

D

UCG – Start

Question 162: Palette 162/182

NEET 2003 MCQ

What would happen if in a gene encoding a polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA ?

A

A polypeptide of 49 amino acids will be formed

B

A polypeptide of 25 amino acids will be formed

C

Two polypeptides of 24 and 25 amino acids will be formed

D

A polypeptide of 24 amino acids will be formed

Question 163: Palette 163/182

NEET 2003 MCQ

During transcription, the DNA site at which RNA polymerase binds is called :-

A

Receptor

B

Regulator

C

Enhancer

D

Promoter

Question 164: Palette 164/182

NEET 2002 MCQ

Transformation experiment was first performed on which bacteria : -

A

Diplococcus pneumoniae

B

Pasteurella pestis

C

E. coli

D

Salmonella

Question 165: Palette 165/182

NEET 2002 MCQ

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

A

RNA polymerase

B

RNA proteases

C

RNA primase

D

RNA ligase

Question 166: Palette 166/182

NEET 2002 MCQ

Change in sequence of nucleotide in DNA is called as -

A

Recombination

B

Mutation

C

Mutagen

D

Translation

Question 167: Palette 167/182

NEET 2002 MCQ

In a DNA percentage of thymine is 20% then what is the percentage of guanine : -

A

40%

B

20%

C

30%

D

60%

Question 168: Palette 168/182

NEET 2002 MCQ

Which of the following enzymes are used to join bits of DNA ?

A

Endonuclease

B

DNA polymerase

C

Ligase

D

Primase

Question 169: Palette 169/182

NEET 2002 MCQ

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

A

Wobbling of codon

B

Universility of codons

C

Overlapping of gene

D

Degeneracy of genetic code

Question 170: Palette 170/182

NEET 2002 MCQ

In E. Coli, during lactose metabolism repressor binds to : -

A

Promoter gene

B

Operator gene

C

Structural gene

D

Regulator gene

Question 171: Palette 171/182

NEET 2002 MCQ

Exon part of m-RNAs have code for : -

A

Lipid

B

Protein

C

Phospholipid

D

Carbohydrate

Question 172: Palette 172/182

NEET 2002 MCQ

Jacob and Monad studied lactose metabolism in E.Coli and proposed operon concept. Operon concept applicable for :

A

All prokaryotes and all eukaryotes

B

All prokaryotes and some protozoanes

C

All prokaryotes

D

All prokaryotes and some eukaryotes

Question 173: Palette 173/182

NEET 2001 MCQ

m-RNA is synthesised on DNA template in which direction : -

A

Any

B

Both (c) and (d)

C

5' → 3'

D

3' → 5'

Question 174: Palette 174/182

NEET 2001 MCQ

Types of RNA polymerase required in nucleus for RNA synthesis : -

A

2

B

3

C

1

D

4

Question 175: Palette 175/182

NEET 2001 MCQ

Gene and cistron words are sometimes used synonymously because : -

A

One gene contains one cistron

B

One cistron contains many gene

C

One gene contains no cistron

D

One gene contains many cistrons

Question 176: Palette 176/182

NEET 2001 MCQ

In Negative operon : -

A

CAMP have negative effect on lac operon

B

Co-repressor binds with inducer

C

Co-repressor binds with repressor

D

Co-repressor does not binds with repressor

Question 177: Palette 177/182

NEET 2000 MCQ

Length of one loop of B- DNA :

A

20 nm.

B

10 nm.

C

3.4 nm.

D

0.34 nm.

Question 178: Palette 178/182

NEET 2000 MCQ

Method of DNA replication in which two strands of DNA separates and synthesize new strands

A

Conservative

B

Non conservative

C

Dispersive

D

Semiconservative

Question 179: Palette 179/182

NEET 2000 MCQ

In three dimensional view the molecule of t-RNA is :

A

E-shaped

B

L-shaped

C

S-shaped

D

Y-shaped

Question 180: Palette 180/182

NEET 2000 MCQ

Which of the following is initiation codon ?

A

AUC

B

CCU

C

UAG

D

AUG

Question 181: Palette 181/182

NEET 2000 MCQ

Anticodon occurs in :

A

DNA

B

r-RNA

C

t-RNA

D

m-RNA

Question 182: Palette 182/182

NEET 2000 MCQ

Similarity in DNA and RNA :

A

Both have similar sugar

B

Both are genetic material

C

Both have similar pyrimidine

D

Both are polymer of nucleotides