Questions and answers for exam Preparation

MCQs

Total Questions : 89 | Page 4 of 9 pages

Question 31. Which of the phage genes are responsible for phage excision?

xis gene
int gene
recA protein
both xis and int gene

Discuss Question

Answer: Option D. -> both xis and int gene
Answer: (d).both xis and int gene

Question 32. Choose the incorrect statement with respect to rolling circle replication.

It is for a single replication fork and yields a concatemeric molecule
Staggered cleavage of DNA takes place at the cos sites
The cleavage generates 10 nucleotide long overhangs
Without the cos sites, the packaging won’t be possible

Discuss Question

Answer: Option C. -> The cleavage generates 10 nucleotide long overhangs
Answer: (c).The cleavage generates 10 nucleotide long overhangs

Question 33. How many phases are there for replication of lambda DNA to take place?

Discuss Question

Answer: Option B. -> 2
Answer: (b).2

Question 34. Insertion vectors are a type of vectors. Choose the correct statement for this type of vector.

These are complex vectors
DNA is inserted through many restriction sites
There is an upper limit on the size of the DNA to be packaged
Lambda gt09 is an example of this type of vector

Discuss Question

Answer: Option C. -> There is an upper limit on the size of the DNA to be packaged
Answer: (c).There is an upper limit on the size of the DNA to be packaged

Question 35. The phase generating additional circular DNA molecules in the first phase does it by __________

bidirectional theta mode
rolling circle mode
separation of the two strands
copying only one strand

Discuss Question

Answer: Option A. -> bidirectional theta mode
Answer: (a).bidirectional theta mode

Question 36. The presence of insert leads to inactivation of which gene?

cII
cI
cIII
both cII and cIII

Discuss Question

Answer: Option B. -> cI
Answer: (b).cI

Question 37. Choose the correct statement for lambda gt10.

It is having an EcoRI site
It is having cII gene
It accepts an insert of size greater than that of 8 kbp
This size is less than that the size which is generally accepted by wild type phage

Discuss Question

Answer: Option A. -> It is having an EcoRI site
Answer: (a).It is having an EcoRI site

Question 38. Choose the incorrect statement for the central portion of the lambda genome.