Questions and answers for exam Preparation

MCQs

Total Questions : 89 | Page 6 of 9 pages

Question 51. Selection of molecules by lack of inserts on the basis of the sacB gene is known as:

positive selection
negative selection
counter selection
sacB selection

Discuss Question

Answer: Option C. -> counter selection
Answer: (c).counter selection

Question 52. F (fertility) factor is used in many bacterial systems for different purposes. Choose the incorrect statement with respect to the F factor.

It was identified in E. coli for catalysing genetic exchange between cells
Cells having F factor are called as female
The F factor is transferred from one cell to another via factors present outside
They are not related to BAC systems

Discuss Question

Answer: Option A. -> It was identified in E. coli for catalysing genetic exchange between cells
Answer: (a).It was identified in E. coli for catalysing genetic exchange between cells

Question 53. F factor integration into the host chromosome is called as __________

F’ plasmid
F factor and host chromosome recombination
Hfr (High frequency of recombination)
Recombinant host chromosome

Discuss Question

Answer: Option C. -> Hfr (High frequency of recombination)
Answer: (c).Hfr (High frequency of recombination)

Question 54. Excision of the F factor can also be done from the host chromosome. Choose the incorrect statement in respect to it.

This excision is possible in vivo
Along with the F factor, host chromosome’s DNA sequences are also excited
The sequences of host chromosome which can be accommodated in the F plasmid are small in size
These plasmids are termed as F’ plasmids

Discuss Question

Answer: Option C. -> The sequences of host chromosome which can be accommodated in the F plasmid are small in size
Answer: (c).The sequences of host chromosome which can be accommodated in the F plasmid are small in size

Question 55. The low copy number of F plasmid is essential for the stability of these plasmids.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 56. Choose the correct statement for BAC vector system.

BAC vector system stands for bacteria and chromosome
It usually accepts insert of size approximately 1000kbp
The repE and oriS sequences are required for controlling the copy number and par A-C sequences are required for replication
A selectable marker is there for chloramphenicol resistance

Discuss Question

Answer: Option D. -> A selectable marker is there for chloramphenicol resistance
Answer: (d).A selectable marker is there for chloramphenicol resistance

Question 57. The bacteriophage M13 vectors belong to a group of phages called as __________

skinny or filamentous phage
M phage group
single stranded phage
double stranded phage

Discuss Question

Answer: Option A. -> skinny or filamentous phage
Answer: (a).skinny or filamentous phage

Question 58. Choose the correct statement for the infection process of M13.

The infectious particle is double stranded
It is contained in a protein coat which is made up of products of gene III or gene VIII
The phage infects only female cells
The phage enters the bacterial cells by the filament which is meant for movement

Discuss Question

Answer: Option B. -> It is contained in a protein coat which is made up of products of gene III or gene VIII
Answer: (b).It is contained in a protein coat which is made up of products of gene III or gene VIII

Question 59. Once the bacteriophage enters the bacterial cells, some changes are carried out in it. Which of the following is not included?

The single stranded molecule entering the cell is single stranded and is called as a + strand
The single stranded molecule is converted into double stranded molecule which is called as replicative form (RF)
It is carried out in a process similar to normal replication process of E. coli
The positive strand is used for the transcription of viral proteins

Discuss Question

Answer: Option D. -> The positive strand is used for the transcription of viral proteins
Answer: (d).The positive strand is used for the transcription of viral proteins

Question 60. Replication can also be carried out by rolling circle replication. Choose the correct statement for this type of replication?