Multiple Choice Questions on Molecular Basis of Inheritance

1. Which one of the following statement is wrong about Diplococcus pneumonia?

a) Inactivated R strains with inactivated S strains does not cause symptoms of disease.

b) Inactivated ‘S’ strains cause symptoms of disease

c) R strains with inactivated S strains cause symptoms of disease.

d) S strains with inactivated R strains cause symptoms of disease

2. For proving the semi conservative mode of replication of DNA E.coli, were first grown in the medium containing

a) ¹⁴NH₃

b) (NH₄ )₂SO4

c) ¹⁵NH₄Cl

d) ¹⁴NH₄Cl

3. E.coli which was grown in the medium containing heavy isotope ¹⁵N for several generations is shifted to normal ¹⁴N medium, the percentage of DNA strands with ¹⁴N isotope after two generations is

a) 12.5 %

b) 50%

c)75%

d) 100%

4. In the above case the percentage of hybrid DNA after 3 generations is

a) 12.5 %

b) 25%

c) 75%

d) 50%

5. If 100 heavy DNA ¹⁵N¹⁵N are replicated three times in ¹⁴N medium, the result obtained is

a) 12.5% intermediate and 87.5% light DNA

b) 25% intermediate and 75 % light DNA

c) 50% heavy and 50% light DNA

d) 37.5 % half heavy and 62.5 heavy DNA

6. Okazaki fragment are

a) Primed by RNA primer

b) formed 5’-3’ direction

c) United to form lagging strand

d) all of these

7. Which is wrong?

a) Alkaptonuria is due to a recessive gene

b) Gene controls in the metabolism

c) In eukaryotes DNA synthesis is faster than prokaryotes

d) Homogentisic acid is excreted in the urine in alkaptonuric patients.

8. The forms of Neurospora crassa which can grown in the minimal medium with additional nutrients is called

a) heterotroph

b) autotroph

c) Auxotroph

d) prototrophs

9. Difference between prokaryotic and eukaryotic ribosomes are due to

a) size

b) nucleotide

c) Sedimentation coefficients

d) Amount of RNA

10. The wrong statement is

a) Transcription occurs in the nucleus in prokaryotes

b) usually monocistronic mRNA is produced in Eukaryotes

c) In prokaryotes the primary mRNA transcript undergoes splicing

d) sigma subunit of RNA polymerase recognises the promoter

Learn more:

• Multiple Choice Questions on Mendelian Genetics
• Multiple Choice on Human Genetic Disorder
• Multiple Choice Questions on Genetics

Answers

1. b) Inactivated ‘S’ strains cause symptoms of disease

2. c) ¹⁵NH₄Cl

3. c) 75%

4. b) 25%
   (In the third generation, total eight DNA molecules are formed. Two of them are hybrids ie
¹⁵N ¹⁴N 2/8 x100 =25%)

5. b) 25% intermediate and 75 % light DNA

6. d) all of these

7. c) In eukaryotes DNA synthesis is faster than prokaryotes

8. c) Auxotroph

9. c) Sedimentation coefficients

10. c) In prokaryotes the primary mRNA transcript undergoes splicing