Questions and answers for exam Preparation

MCQs

Total Questions : 89 | Page 2 of 9 pages

Question 11. Choose the correct statement for the lambda ZAP vector.

It is not based on bacteriophage lambda
It contains a region that can be excised in vivo
The excision leads to the formation of bluescript plasmids and it contains an initiator region only
The multiple cloning site is not flanked by the initiator and the terminator region

Discuss Question

Answer: Option B. -> It contains a region that can be excised in vivo
Answer: (b).It contains a region that can be excised in vivo

Question 12. Choose the correct statement for cosmids.

It can be regarded as lambda substitution vector
Less amount of phage DNA is deleted
Only cos packaging sites are left
It doesn’t contains a origin of replication

Discuss Question

Answer: Option C. -> Only cos packaging sites are left
Answer: (c).Only cos packaging sites are left

Question 13. Which of the following doesn’t takes place after replication?

The single stranded sequence is generated
It is circularized to form closed single stranded molecule
It may circularize or remain linear
The double stranded molecule can be synthesized by cellular DNA synthesis

Discuss Question

Answer: Option C. -> It may circularize or remain linear
Answer: (c).It may circularize or remain linear

Question 14. The initiator is recognized by which gene?

Gene I
Gene I and II
Only gene II
Gene III

Discuss Question

Answer: Option C. -> Only gene II
Answer: (c).Only gene II

Question 15. Choose the incorrect statement for the replication process.

The initiator site is nicked and replication of one strand is started
Replication takes place in both the directions
Replication continues through the bluescript
It is stopped at the terminator and then again a nick is made

Discuss Question

Answer: Option B. -> Replication takes place in both the directions
Answer: (b).Replication takes place in both the directions

Question 16. Which of the following is a restriction for cloning in bacteriophage Mu?

It is limited to handling only small number of phage particles
It relies on whether the DNA is flanked by two mini Mu genes or not
Recombination between the elements in the second strain is not a restriction
Fragments of any genomic DNA can be cloned irrespective of the fact whether or not the phage can replicate in it or not

Discuss Question

Answer: Option B. -> It relies on whether the DNA is flanked by two mini Mu genes or not
Answer: (b).It relies on whether the DNA is flanked by two mini Mu genes or not

Question 17. What is the function of the pac site in the bacteriophage PI?

It is responsible for the initiation of packaging
It is responsible for the termination of packaging
It is responsible for the initiation of replication
It is responsible for the termination of replication

Discuss Question

Answer: Option A. -> It is responsible for the initiation of packaging
Answer: (a).It is responsible for the initiation of packaging

Question 18. What is the function of loxP sites?

It is responsible for linearization of DNA in the host bacterium
It is responsible for circularization of DNA in the host bacterium
It is responsible for conversion of single stranded DNA into double stranded DNA
It is responsible for conversion of double stranded DNA into single stranded DNA

Discuss Question

Answer: Option B. -> It is responsible for circularization of DNA in the host bacterium
Answer: (b).It is responsible for circularization of DNA in the host bacterium

Question 19. Which of the following is not included as a step in cloning in bacteriophage PI?

The growth of vector is done as a plasmid by using pBR322 origin of replication
Cleaving with BamH1 is done and then products cleaved with Sau3A are ligated
Incubation with mutant lysogen is done which doesn’t cleaves the recombinants at pac sites
Incubation is done with mutant lysogen which doesn’t contains head and tail proteins

Discuss Question

Answer: Option C. -> Incubation with mutant lysogen is done which doesn’t cleaves the recombinants at pac sites
Answer: (c).Incubation with mutant lysogen is done which doesn’t cleaves the recombinants at pac sites

Question 20. What is the size of the insert that can be accommodated in the head of bacteriophage PI?