MCQ Questions on Molecular Biology

MCQ Questions on Molecular Biology

1. The function of β subunit of polymerase is
(a) Template binding
(b) Catalytic binding
(c) Promoter binding
(d) Cation binding

Answer

Answer: (b) Catalytic binding


2. Which of the σ factors is heat stable?
(a) σ 54
(b) σ 70
(c) σ 28
(d) σ 32

Answer

Answer: (d) σ 32


3. The mRNA codon of valine is
(a) GUC
(b) UGG
(c) CCA
(d) TTG

Answer

Answer: (a) GUC


4. True replication of DNA is due to
(a) Phosphate backbone
(b) Hydrogen bonding
(c) Complementary base pairing rule
(d) None

Answer

Answer: (c) Complementary base pairing rule


5. Which of the following statements is not applicable to viruses?
(a) The virus replicates in a bacterial host
(b) The protein coat of a virus does not enter the host cell
(c) The genetic material is DNA or RNA
(d) Virus replicate autonomously in the absence of host

Answer

Answer: (d) Virus replicate autonomously in the absence of host


6. Mode of DNA replication is
(a) Conservative and bidirectional
(b) Semiconservative and unidirectional
(c) Semiconservative and bidirectional
(d) Conservative and unidirectional

Answer

Answer: (c) Semiconservative and bidirectional


7. Which enzyme is used to join nicks in the DNA strand?
(a) Primase
(b) DNA polymerase
(c) DNA ligase
(d) Endonuclease

Answer

Answer: (c) DNA ligase


8. Which enzyme is used in the unwinding of DNA?
(a) Ligase
(b) Topoisomerase
(c) Helicase
(d) Exonuclease

Answer

Answer: (c) Helicase


9. Which of the following processes does not occur in prokaryotes?
(a) Transcription
(b) Splicing
(c) Translation
(d) Replication

Answer

Answer: (b) Splicing


10. cDNA is synthesised from RNA by the enzyme
(a) DNA polymerase
(b) DNA synthetase
(c) DNA convertase
(d) Reverse transcriptase

Answer

Answer: (d) Reverse transcriptase


11. Which of the following base-pairing rule is correct?
(a) Adenine with guanine and thymine with cytosine
(b) DNA base pairing is non-specific
(c) Adenine with cytosine and guanine with thymine
(d) Adenine with thymine and guanine with cytosine

Answer

Answer: (d) Adenine with thymine and guanine with cytosine


12. DNA synthesis can be measured by estimating the incorporation of radiolabelled
(a) Thymine
(b) Guanine
(c) Cytosine
(d) Adenine

Answer

Answer: (a) Thymine


13. How many RNA polymerases are present in a bacterial system?
(a) 4
(b) 2
(c) 1
(d) 3

Answer

Answer: (c) 1


14. During DNA replication the synthesis of the leading strand of DNA results in fragments known as
(a) Okazaki fragments
(b) Satellite segments
(c) Kornberg segment
(d) Double-helix segment

Answer

Answer: (a) Okazaki fragments


15. Short strands of ——- primer are used in DNA replication.
(a) DNA
(b) RNA
(c) Histone
(d) Protein

Answer

Answer: (b) RNA


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