Explore topic-wise MCQs in Molecular Biology.

This section includes 20 Mcqs, each offering curated multiple-choice questions to sharpen your Molecular Biology knowledge and support exam preparation. Choose a topic below to get started.

1.

In SOS repair system cleavage of LexA and UmuD is mediated by ___________

A. RecB
B. RecA
C. RecC
D. UvrA
Answer» C. RecC
Discussion
2.

In eukaryotes the other name of PCNA is __________

A. Sliding clamp
B. Sliding clamp loader
C. Replicative DNA polymerase
D. Translesional DNA polymerase
Answer» B. Sliding clamp loader
Discussion
3.

The genes encoding the translesional polymerases are expressed as part of a pathway known as the SOS response.

A. True
B. False
Answer» B. False
Discussion
4.

In humans which DNA polymerase is involved?

A. DNA polymerase ƞ
B. DNA polymerase α
C. DNA polymerase β
D. DNA polymerase ν
Answer» B. DNA polymerase α
Discussion
5.

What is the main enzyme that plays a major role in formation of thymine dimer?

A. DNA glycosylase
B. DNA photolyase
C. DNA gyrase
D. DNA ligase
Answer» C. DNA gyrase
Discussion
6.

IN_HUMAN_WHICH_DNA_POLYMERASE_IS_INVOLVED??$

A. DNA polymerase ∆û
B. DNA polymerase α
C. DNA polymerase β
D. DNA polymerase ν
Answer» B. DNA polymerase ‚âà√≠¬¨¬±
Discussion
7.

In eukaryotes the other name of PCNA is __________$

A. Sliding clamp
B. Sliding clamp loader
C. Replicative DNA polymerase
D. Translesional DNA polymerase
Answer» B. Sliding clamp loader
Discussion
8.

The_genes_encoding_the_translesional_polymerases_are_expressed_as_part_of_a_pathway_known_as_the_SOS_response.$

A. True
B. False
Answer» B. False
Discussion
9.

In the following compounds which are involved in nucleotide excision repair?

A. UvrA, UvrB, UvrC
B. UvrC, UvrD
C. Uvr C, XPA, XPD
D. XPA, XPC, XPD, XPG
Answer» E.
Discussion
10.

NHEJ is ubiquitin independent in eukaryotic organisms.

A. True
B. False
Answer» C.
Discussion
11.

What are the two fundamental components of NHEJ?

A. KU70, KU80
B. KU50, KU70
C. KU40, KU50
D. KU30, KU40
Answer» B. KU50, KU70
Discussion
12.

In_SOS_repair_system_cleavage_of_LexA_and_UmuD_is_mediated_by____________

A. RecB
B. RecA
C. RecC
D. UvrA
Answer» C. RecC
Discussion
13.

Which complex in E. coli performs in translesion synthesis?

A. DNA polymerase IV, DNA polymerase V
B. DNA polymerase II, DNA polymerase III
C. DNA polymerase III, DNA polymerase IV
D. DNA polymerase V, RNA polymerase I
Answer» B. DNA polymerase II, DNA polymerase III
Discussion
14.

After creation of the bubble which Uvr component are recruited?

A. Uvr B
B. Uvr A
C. Uvr C
D. Uvr D
Answer» D. Uvr D
Discussion
15.

Which two Uvr component molecules scan the DNA during nucleotide excision repair?

A. UvrC, UvrA
B. UvrA, UvrB
C. UvrB, UvrC
D. UvrD, UvrA
Answer» C. UvrB, UvrC
Discussion
16.

What is the main enzyme that plays the major role in formation of thymine dimer?

A. DNA glycosylase
B. DNA photolyase
C. DNA gyrase
D. DNA ligase
Answer» C. DNA gyrase
Discussion
17.

Which enzyme is activated during double stranded break?

A. DNA polymerase
B. Translesional polymerase
C. RNA polymerase
D. Klenow fragment
Answer» C. RNA polymerase
Discussion
18.

Why recombinational repair system is called double strand break repair?

A. Both strands are broken
B. One strand is broken
C. No strand is broken
D. Both strand act as template
Answer» B. One strand is broken
Discussion
19.

How many types of excision repair systems are known?

A. 1
B. 2
C. 3
D. 4
Answer» C. 3
Discussion
20.

What is the correct definition of excision repair?

A. Repair of a single damaged nucleotide
B. Repair of a damaged oligonucleotide
C. Removal of a single damaged nucleotide
D. Removal of a damaged oligonucleotide
Answer» D. Removal of a damaged oligonucleotide
Discussion