Answers
1. Both strands of DNA serve as templates concurrently in
A. replication
B. excision repair
C. mismatch repair
D.
None of these
Answer: A
2. Proofreading activity to maintain the fidelity of DNA synthesis
A. occurs after the synthesis has been completed
B. is a function of the 3?-5? exonuclease activity in the DNA polymerases
C. requires the presence of an enzyme separate from the DNA polymerases
D.
Occurs in prokaryotes but not eukaryotes
Answer: B
3. Which of the following repairs nicked DNA by forming a phosphodiester bond between adjacent nucleotides?
A. Helicase
B. DNA gyrase
C. Topoisomerases
D.
DNA ligase
Answer: D
4. The enzyme that catalyzes the synthesis of DNA is called
A. DNA polymerase
B. DNA gyrase
C. DNA ligase
D.
Helicase
Answer: A
5. Which of the following possesses both 5?-3? and 3?-5? exonuclease activity?
A. Kornberg enzyme
B. DNA polymerase III
C. Taq DNA polymerase
D.
None of these
Answer: A
6.During which of the following process a new copy of a DNA molecule is precisely synthesized?
A. Trasformation B. Transcription
C. Translation D. Replication
Answer: D
7.Which of the following enzymes unwind short stretches of DNA helix immediately ahead of a replication fork?
A.
DNA polymerases
B. Helicases
C. Single-stranded binding proteins
D. Topoisomerases
Answer: B
8.Which of the following lacks 3?-5? exonuclease activity?
A. Short fragment of DNA polymerase I
B.
Taq DNA polymerase
C. T4 DNA ligase
D. All of the above
Answer: D
9.The synthesis of DNA by DNA polymerase occurs in the
A. 3? to 5? direction
B. 5? to 5? direction
C.
5? to 3? direction
D. 3? to 3? direction
Answer: C
10.True replication of DNA is possible due to
A Hydrogen bonding
B Phosphate backbone
C Complementary base pairing rule
D None of the above.
Answer C
11.The elongation of the leading strand during DNA synthesis
A Progresses away from the replication fork
B Occur in 3’-5’ direction
C Produces Okazaki fragment
D Depend on the action of DNA polymerase
Answer D.
12.During the replication of DNA, the synthesis of DNA on lagging strand takes place in segments, these segments are called
A Satellite segments
B Double helix segments
C Kornbeg segments
D Okazaki segments
Answer D
13.When DNA replication starts
A The phosphodiester bonds between the adjacent nucleotides break
B The bonds between the nitrogen base and deoxyribose sugar break
C The leading strand produces Okazaki fragments
D The hydrogen bonds between the nucleotides of two strand break
Answer D
.