Questions and answers for exam Preparation

MCQs

Total Questions : 71 | Page 7 of 8 pages

Question 61. Which of the characteristics is present in lacZ gene?

It encodes for beta galactosidase enzyme
Beta galactosidase enzyme is responsible for cleaving monosaccharides into the constituent elements
It doesn’t cleaves a substrate called as X-gal
But if X-gal is cleaved, it liberates pink coloured dye

Discuss Question

Answer: Option A. -> It encodes for beta galactosidase enzyme
Answer: (a).It encodes for beta galactosidase enzyme

Question 62. The phenomenon of alpha complementation is __________

α + β = ω
α = β + ω
β = α + ω
It is either α + β = ω or β = α + ω

Discuss Question

Answer: Option A. -> α + β = ω
Answer: (a).α + β = ω

Question 63. An operon is defined as __________

A related set of genes each having different promoters and are present differently
A set of genes which are present together but are controlled by different promoters
A set of genes which are present together and are controlled by the same promoter
A set of genes which are not present together but controlled by the same promoter

Discuss Question

Answer: Option C. -> A set of genes which are present together and are controlled by the same promoter
Answer: (c).A set of genes which are present together and are controlled by the same promoter

Question 64. What will be the consequence of not having an origin of replication (ori) in the vector?

If an ori is absent, replication of vector would not take place
As the cells divide after taking up the vector, both the daughter cells would be having the vector
A colony of transformed colonies is observed
The vector won’t be taken up by the cell

Discuss Question

Answer: Option A. -> If an ori is absent, replication of vector would not take place
Answer: (a).If an ori is absent, replication of vector would not take place

Question 65. Why the whole lacZ gene can’t be present in the plasmid at one time?

Because the whole lacZ gene can’t be present anywhere
The whole lac Z gene is very large in size and the plasmid size is small
The whole lacZ gene is never functional
Because the plasmid takes is having a restriction site only for taking up a portion of the lacZ gene

Discuss Question

Answer: Option B. -> The whole lac Z gene is very large in size and the plasmid size is small
Answer: (b).The whole lac Z gene is very large in size and the plasmid size is small

Question 66. Alpha complementation is an indicator of lacZ system. Which of the statement is incorrect for it?

One portion of the lacZ gene known as minigene is present in the plasmid
Another portion is present in the host itself
If they both are allowed to combine in the presence of IPTG, X-gal and ampicillin, blue colonies are observed
If insert is also present along with host and plasmid, it results in the formation of blue colonies

Discuss Question

Answer: Option D. -> If insert is also present along with host and plasmid, it results in the formation of blue colonies
Answer: (d).If insert is also present along with host and plasmid, it results in the formation of blue colonies

Question 67. Some mutations are present which assist the uptake of DNA. Which of the statement is incorrect for it?

deoR is such a mutation which assists the uptake of DNA
It is a transcriptional regulator
It is having DNA binding activity
It controls the expression of a set of genes involved ribonucleoside catabolism

Discuss Question

Answer: Option D. -> It controls the expression of a set of genes involved ribonucleoside catabolism
Answer: (d).It controls the expression of a set of genes involved ribonucleoside catabolism

Question 68. Which of the following is true for K strain for E. coli?

It contains restriction-modification system which is encoded by hsDMRS locus
hsDR encodes for endonuclease which is responsible for cleaving the DNA sequence containing –AACGCNNTGC-
Cleavage is carried out when the second A is non methylated
hsDR mutation can be used for cleavage of incoming unprotected DNA

Discuss Question

Answer: Option A. -> It contains restriction-modification system which is encoded by hsDMRS locus
Answer: (a).It contains restriction-modification system which is encoded by hsDMRS locus

Question 69. The cell in which the recombinant molecules are propagated is termed as __________