Questions and answers for exam Preparation

MCQs

Total Questions : 71 | Page 5 of 8 pages

Question 41. Disablement is also done in plasmids. Choose the correct statement.

The strains carrying out the recombinant plasmids should not escape outside
Preferred strains are having mutations which allow their growth in wild
Mutations confer prototrophy
If the recombinants escape outside, there is no such harm

Discuss Question

Answer: Option A. -> The strains carrying out the recombinant plasmids should not escape outside
Answer: (a).The strains carrying out the recombinant plasmids should not escape outside

Question 42. The correct statement with respect to lacIq is __________

It is a mutant of lac repressor gene and decreases the level of repressor
It doesn’t control the lacZ gene
It is important for the vectors to replicate in a low copy number
It doesn’t titrate out the repressor produced by wild type Lac-I gene

Discuss Question

Answer: Option A. -> It is a mutant of lac repressor gene and decreases the level of repressor
Answer: (a).It is a mutant of lac repressor gene and decreases the level of repressor

Question 43. There are various methods to distinguish whether a colony contains a recombinant or not. One such method is __________

blue white screening
checking whether replication is taking place or not
checking the number of copies
looking for the multiple cloning site

Discuss Question

Answer: Option A. -> blue white screening
Answer: (a).blue white screening

Question 44. Alkaline Phosphatase is used at times and the vector is treated with it. Choose the incorrect statement.

It removes 5’ terminal phosphate group from nucleic acids
The 5’ phosphate group is required for the ligation to take place
Two phosphate bonds should be formed for the complete ligation to take place
The ligation between vector and insert won’t take place

Discuss Question

Answer: Option D. -> The ligation between vector and insert won’t take place
Answer: (d).The ligation between vector and insert won’t take place

Question 45. At times it is observed that non-recombinant plasmids are more than that of recombinant plasmids. Choose the correct statement in regard to it.

It makes easier to get the recombinant plasmids from the mixture
The ratio of insert DNA to vector DNA is reduced to get recombinant plasmids
Alkaline phosphatase is used to get recombinant plasmids
Alkaline phosphatase method is less reliable in comparison to the ratio method

Discuss Question

Answer: Option C. -> Alkaline phosphatase is used to get recombinant plasmids
Answer: (c).Alkaline phosphatase is used to get recombinant plasmids

Question 46. What is the correct time for carrying out the alkaline phosphatase treatment?

After the cutting of vector has been done
Before the insert DNA and the vector are mixed
After the cutting of vector has been done but before the insert DNA and vector are mixed
After the mixing of insert DNA and vector

Discuss Question

Answer: Option C. -> After the cutting of vector has been done but before the insert DNA and vector are mixed
Answer: (c).After the cutting of vector has been done but before the insert DNA and vector are mixed

Question 47. Transformation efficiency is defined as __________

ratio of transformed colonies by microgram of sample DNA that is to be inserted
ratio of transformed colonies by amount of sample DNA that is to be inserted
ratio of transformed colonies by microgram of plasmid DNA
ratio of transformed colonies by amount of plasmid DNA

Discuss Question

Answer: Option D. -> ratio of transformed colonies by amount of plasmid DNA
Answer: (d).ratio of transformed colonies by amount of plasmid DNA

Question 48. Choose the correct statement for adaptors.

They are blunt ended at both the ends
They are single stranded at both the ends
They may be single stranded at one end and other end may be blunt
They don’t have extra restriction sites within their sequence

Discuss Question

Answer: Option C. -> They may be single stranded at one end and other end may be blunt
Answer: (c).They may be single stranded at one end and other end may be blunt

Question 49. After carrying out the cloning experiment, the cells are plated on agar. Along with agar, it also contains antibiotic resistant genes, X-gal and an inducer of lacZ gene. Which of the following would grow?

Cells that have taken up plasmid DNA
Cells that have taken up genomic DNA
Cells having no insert
Cells having no insert

Discuss Question

Answer: Option A. -> Cells that have taken up plasmid DNA
Answer: (a).Cells that have taken up plasmid DNA

Question 50. Plasmids are used for carrying out the cloning procedure. Which of the statement is true for plasmids?

Bacterial plasmids are linear in nature
They are single stranded
Insertion of DNA into plasmid allows it to be propagated in host cells and they are known as vectors because of their this property
They are not capable of replication in bacteria

Discuss Question

Answer: Option C. -> Insertion of DNA into plasmid allows it to be propagated in host cells and they are known as vectors because of their this property
Answer: (c).Insertion of DNA into plasmid allows it to be propagated in host cells and they are known as vectors because of their this property