Questions and answers for exam Preparation

MCQs

Total Questions : 101 | Page 6 of 11 pages

Question 51. The DNA polymerase in bacteria, responsible for DNA synthesis is

Polymerase I
Polymerase III
all of these
Polymerase II

Discuss Question

Answer: Option B. -> Polymerase III

Question 52. The nicks or gaps between Okazaki fragments are eventually sealed by

DNA ligase
RNA ligase
gyrase
polymerase

Discuss Question

Answer: Option A. -> DNA ligase

Question 53. In a typical electrophoresis experiment, larger fragments of DNA move more

slowly, so they appear nearer the bottom of a gel photograph
slowly, so they appear nearer the top of a gel photograph
quickly, so they appear nearer the top of a gel photograph
quickly, so they appear nearer the bottom of a gel photograph

Discuss Question

Answer: Option B. -> slowly, so they appear nearer the top of a gel photograph

Question 54. 30 nm wide helix with five or six nucleosomes per helix is known as

halonoid
none of these
solenoid
kinoplast

Discuss Question

Answer: Option C. -> solenoid

Question 55. Nucleosome is

an octamer of four histones without H1 protein
an hexamer of three histones with H1 protein
an octamer of four histones with H1 protein
an hexamer of three histones without H1 protein

Discuss Question

Answer: Option A. -> an octamer of four histones without H1 protein

Question 56. Which of the following is used to determine the appropriate stringency (Wallace rule)?

Tm = 4 x (No.of G:C base pair) + 2 x (No.of A:T base pair)
Tm = 2 x (No.of G:C base pair) + 4 x (No.of A:T base pair)
Tm = 4 x (No.of A:T base pair) + 2 x (No.of G:C base pair)
Tm = 69.3° + 0.41 (%)G+C -650/1

Discuss Question

Answer: Option A. -> Tm = 4 x (No.of G:C base pair) + 2 x (No.of A:T base pair)

Question 57. The melting of 40-45 bp at the oriC site of E. coli requires

DNA + ATP + HU + DNAb + DNAa + Pol III holoenzyme
DNA + ATP + HU
DNA + ATP + HU + DNAb
DNA+ ATP + HU + DNAb + DNAa

Discuss Question

Answer: Option B. -> DNA + ATP + HU

Question 58. DNA polymerases I also has

5'-3' endonuclease activity
3'-5'exonuclease activity
both (a) and (b)
5'-3' exonuclease activity

Discuss Question

Answer: Option B. -> 3'-5'exonuclease activity

Question 59. Without telomerase, what would happen to the ends of chromosomes after each round of replication?

Chromosomes would become progressively shorter
Nothing would happen
None of these
Chromosomes would get longer

Discuss Question

Answer: Option A. -> Chromosomes would become progressively shorter

Question 60. One hypothesis of DNA replication suggested that the parental DNA molecules are broken into fragments. Both strands of DNA in each of the daughter molecules are made up of an assortment of parental and new DNA. This statement refers to which hypothesis?