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NUCLEIC ACIDS- Part 10
See all quizzes of NUCLEIC ACIDS- Part 10 here:
1 During replication, the template DNA is
unwound
(A) At one of the ends (B) At both the ends
(C) At multiple sites (D) Nowhere
2. During replication, unwinding of double
helix is initiated by
(A) DNAA protein (B) DnaB protein
(C) DNAC protein (D) Rep protein
3. For unwinding of double helical DNA,
(A) Energy is provided by ATP
(B) Energy is provided by GTP
(C) Energy can be provided by either ATP or GTP
(D) No energy is required
4. Helicase and DNAB protein cause
(A) Rewinding of DNA and require ATP as a
source of energy
(B) Rewinding of DNA but do not require any
source of energy
(C) Unwinding of DNA and require ATP as a
source of energy
(D) Unwinding of DNA but do not require any
source of energy
5. The unwound strands of DNA are held
apart by
(A) Single strand binding protein
(B) Double strand binding protein
(C) Rep protein
(D) DNAA protein
6. Deoxyribonucleotides are added to RNA
primer by
(A) DNA polymerase I
(B) DNA polymerase II
(C) DNA polymerase III holoenzyme
(D) All of these
7. Ribonucleotides of RNA primer are replaced
by deoxyribonucleotides by the
enzyme:
(A) DNA polymerase I
(B) DNA polymerase II
(C) DNA polymerase III holoenzyme
(D) All of these
8. DNA fragments are sealed by
(A) DNA polymerase II
(B) DNA ligase
(C) DNA gyrase
(D) DNA topoisomerase II
9. Negative supercoils are introduced in DNA
by
(A) Helicase
(B) DNA ligase
(C) DNA gyrase
(D) DNA polymerase III holoenzyme
10. Reverse transcriptase activity is present
in the eukaryotic:
(A) DNA polymerase α
(B) DNA polymerase γ
(C) Telomerase
(D) DNA polymerase II
11. DNA polymerase III holoenzyme possesses
(A) Polymerase activity
(B) 3’→5’ Exonuclease activity
(C) 5’→3’ Exonuclease and polymerase activities
(D) 3’→5’ Exonuclease and polymerase activities
12. DNA polymerase I possesses
(A) Polymerase activity
(B) 3’→5’ Exonuclease activity
(C) 5’→3’ Exonuclease activity
(D) All of these
13. 3’→5’ Exonuclease activity of DNA
polymerase I
(A) Removes ribonucleotides
(B) Adds deoxyribonucleotides
(C) Corrects errors in replication
(D) Hydrolyses DNA into mononucleotides
14. All of the following statements about
RNA-dependent DNA polymerase are true
except:
(A) It synthesizes DNA using RNA as a template
(B) It is also known as reverse transcriptase
(C) It synthesizes DNA in 5’→3’ direction
(D) It is present in all the viruses
15. Reverse transcriptase catalyses
(A) Synthesis of RNA
(B) Breakdown of RNA
(C) Synthesis of DNA
(D) Breakdown of DNA
16. DNA A protein can bind only to
(A) Positively supercoiled DNA
(B) Negatively supercoiled DNA
(C) Both (A) and (B)
(D) None of these
17. DNA topoisomerase I of E. coli catalyses
(A) Relaxation of negatively supercoiled DNA
(B) Relaxation of positively supercoiled DNA
(C) Conversion of negatively supercoiled DNA
into positively supercoiled DNA
(D) Conversion of double helix into supercoiled
DNA
18. In mammalian cell cycle, synthesis of DNA
occurs during
(A) S phase (B) G1 phase
(C) Mitotic Phase (D) G2 phase
19. Melting temperature of DNA is the temperature
at which
(A) Solid DNA becomes liquid
(B) Liquid DNA evaporates
(C) DNA changes from double helix into
supercoiled DNA
(D) Native double helical DNA is denatured
20. Melting temperature of DNA is increased
by its
(A) A and T content (B) G and C content
(C) Sugar content (D) Phosphate content
21. Buoynat density of DNA is increased by
its
(A) A and T content (B) G and C content
(C) Sugar content (D) None of these
22. Relative proportions of G and C versus A
and T in DNA can be determined by its
(A) Melting temperature
(B) Buoyant density
(C) Both (A) and (B)
(D) None of these
23. Some DNA is present in mitochondria of
(A) Prokaryotes (B) Eukaryotes
(C) Both (A) and (B) (D) None of these
24. Satellite DNA contains
(A) Highly repetitive sequences
(B) Moderately repetitive sequences
(C) Non-repetitive sequences
(D) DNA-RNA hybrids
25. Synthesis of RNA and a DNA template is
known as
(A) Replication (B) Translation
(C) Transcription (D) Mutation
26. Direction of RNA synthesis is
(A) 5′ → 3’ (B) 3′ → 5’
(C) Both (A) and (B) (D) None of these
27. DNA-dependent RNA polymerase is a
(A) Monomer (B) Dimer
(C) Trimer (D) Tetramer
28. DNA-dependent RNA polymerase requires
the following for its catalytic activity:
(A) Mg++ (B) Mn++
(C) Both (A) and (B) (D) None of these
29. The initiation site for transcription is
recognized by
(A) α−Subunit of DNA-dependent RNA polymerase
(B) β−Subunit of DNA-dependent RNA polymerase
(C) Sigma factor
(D) Rho factor
30. The termination site for transcription is
recognized by
(A) α−Subunit of DNA-dependent RNA polymerase
(B) β−Subunit of DNA-dependent RNA polymerase
(C) Sigma factor
(D) Rho factor
