MCQ on Genetics

MCQ for Practice :-

1) Genomic Library is constructed by a - 

a) Electrophoresis

b)PCR

c) Shotgun experiment

d)Heat denaturation

Ans :- C) Shotgun experiment

2) Cloning of gene is also called - 

a)Gene therapy

b)Gene modification

c)Gene tampering 

d)Gene amplification 

Ans :- D) Gene amplification

3) C DNA is called -

a)True copy of mRNA molecule 

b)True copy of tRNA molecule

c)True Copy of rRNA molecule

d)Coloured DNA molecule

Ans :- A) True copy of mRNA molecule

4) A base sequence of the DNA probe is complementary to -

a)only m-RNA 

b)The DNA strand to be detected

c)Non-genetic RNA

d)ds- DNA 

Ans :- B) The DNA strand to be detected

5) The C-DNA is synthesized from m-RNA by an enzyme -

a)Transcriptase 

b)RNA polymerase

c) DNA gyrase

d)Reverse transcriptase

Ans :- D) Reverse transcriptase

6) During transcription, RNA polymerase binds to DNA site-

a)Regulator 

b)Promoter 

c)Receptor

d)Enhancer

Ans :- B) Promoter

7) What does lac refer to in lac operon -

a)Lactose

b)Lac insect 

c)1,00,000

d)Lactase

Ans :- (A) Lactose

8) In Lac operon, lactose acts as - 

a)Inducer 

b)Co-inducer 

c)Repressor

d)Co-repressor 

Ans :- A) Inducer

9) A gene of operon which forms the repressor Protein is :-

a)Operator 

b)Regulator

c)Structural

d)Promoter

Ans :- B) Regulator

10) In lac operon system, lac gene-1 codes for - 

a)Promoter

b)Repressor

c)Inducer

d)β-galactosidase

Ans :- D) β-galactosidase

11) Sequence of structural gene of lac operon is - 

a)A,Z,Y

b)Z,Y,A

c)A,Y,Z

d)Y,Z,A

Ans :- B) Z,Y,A

12) A unit of lac-operon which in the absence of lactose, suppresses the activity of operator gene is - 

a)Structural gene

b)Regulatory gene 

c)Repressor protein

d)Promoter gene

Ans :- B) Regulatory gene

13) A Complete turns in 45000 bp DNA would be -

a)45

b)450

c)4500

d)45,000

Ans :- C) 4500

14) How many times the DNA can replicate in a life of a cell?

a)Only once

b)Several time

c) Twice

d)Depends on Ploidy level

Ans :- A) Only once

15) A gyre of DNA Consist 40% Adenine bases, the number of hydrogen bonds are likely to be -

a)30

b)32

c)22

d)16

Ans :- C) 22

16) The base composition of sperm of human DNA consists of 31% Adenine & 19% Guanine. The quantity of cytosine in human somatic cell is likely to be -

a)19%

b)38%

c)31%

d)9.5%

Ans :- A) 19%

17) A double stranded DNA molecule consists 18% Thymine. What is the percentage of cytosine?

a)18%

b)36%

c)64%

d)32%

Ans :- D) 32%

18) Portion of gene which is transcribed but not translated is -

a)Exon

b)Intron

c)Cistron

d)Codon

Ans :- B) Intron

19) Exon segments are reunited after splicing by- 

a)RNA Primase

b)RNA Polymerase

c)RNA Protease

d)RNA Ligase

Ans :- B) RNA Polymerase

20) Site for protein synthesis is :- 

a)Nucleus

b)Cytosol

c)Ribosome

d)Lysosome

Ans :- C) Ribosome

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