Recombinant DNA Technology MCQ Questions & Answers

1.
If bacterial cells are transformed with a mixture of linear and circular molecules resulting from a ligation reaction designed to produce a recombinant molecule

A. No recombinant molecule will ever be detected

B. Both linear and circular molecules will replicate equally well

C. None of the plasmids will express the antibiotic resistance gene located on the plasmid

D. The circular molecules will be amplified by the cells

Answer & Solution Discuss in Board Save for Later

2.
A recombinant protein is to be expressed under the control of the lac promoter and operator in a strain of E. coli having the genotype lacI⁺ crp⁺. Even in the absence of inducer IPTG, low levels of expression of the recombinant protein are seen (leaky expression). Which one of the following should be done to minimize such leaky expression?

A. Addition of lactose to the medium

B. Removal of all glucose from the medium

C. Addition of excess glucose to the medium

D. Addition of allo-lactose to the medium

Answer & Solution Discuss in Board Save for Later

3.
Determine the correctness or otherwise of the following Assertion [A] and the Reason [R].
Assertion [A]: Dam methylase protects E. coli DNA from phage endonucleases.
Reason [R]: E. coli Dam methylase methylates the adenosine residue in the sequence "GATC".

A. Both [A] and [R] are true and [R] is the correct reason for [A]

B. Both [A] and [R] are true but [R] is not the correct reason for [A]

C. Both [A] and [R] are false

D. [A] is false but [R] is true

Answer & Solution Discuss in Board Save for Later

4.
The schematic of a plasmid with a gap in one of the strands is shown below:
Which of the following enzyme(s) is/are required to fill the gap and generate a covalently closed circular plasmid?
P. DNA ligase
Q. Alkaline phosphatase
R. DNA polymerase
S. Polynucleotide kinase

A. P only

B. P, R and S only

C. P and R only

D. P, Q and R only

Answer & Solution Discuss in Board Save for Later

5.
Match the following genetic elements with their functions.

Genetic elements Functions

P. neo^R 1. Facilitates inducible expression of genes in eukaryotes.

Q. SV40 2. Facilitates constitutive expression of genes in eukaryotes.

R. LTR 3. Allows amplification of gene.

S. S. dhfr. 4. Provides way of selecting eukaryotic cells, which have received foreign DNA.

A. P-4, Q-2, R-1, S-3

B. P-2, Q-4, R-1, S-3

C. P-1, Q-4, R-2, S-3

D. P-4, Q-2, R-3, S-1

Answer & Solution Discuss in Board Save for Later

6.
cDNA made from the mRNA of an organism was used to make a cDNA library in a vector that allows the expression as a fusion with a reporter tag. What percentage of the cDNA clones is likely to give rise to correct gene products?

A. 10%

B. 30%

C. 50%

D. 100%

Answer & Solution Discuss in Board Save for Later

7.
Commonly used reporter gene in plant expression vectors is

A. Ti gene of Agrobacterium tumifaciens

B. Gus gene

C. β-lactamase gene

D. α-amylase gene

Answer & Solution Discuss in Board Save for Later

8.
EcoRI restriction sites on a 10kb DNA fragment are shown below
Upon partial digestion, what are the lengths (in kb) of all the possible DNA fragments obtained?

A. 2, 3, 4, 5, 6, 7, 8, and 10

B. 2, 3, 4, 5, 6 and 7

C. 2, 3, 4 and 7

D. 2 and 3

Answer & Solution Discuss in Board Save for Later

9.
What are the experimental steps needed for screening an expression library for clone encoding a protein X that has been isolated and purified?
P. mRNA isolation
Q. Antibody preparation
R. Cloning into an appropriate vector
S. Western blotting on transferred plaques

A. P, S

B. Q, S

C. Q, R

D. R, S

Answer & Solution Discuss in Board Save for Later

10.
The basis for blue-white screening with pUC vectors is

A. Intraallelic complementation

B. Intergenic complementation

C. Intragenic suppression

D. Extragenic suppression

Answer & Solution Discuss in Board Save for Later

Genetic elements	Functions
P. neo^R	1. Facilitates inducible expression of genes in eukaryotes.
Q. SV40	2. Facilitates constitutive expression of genes in eukaryotes.
R. LTR	3. Allows amplification of gene.
S. S. dhfr.	4. Provides way of selecting eukaryotic cells, which have received foreign DNA.

Recombinant DNA Technology MCQ Questions & Answers | Biotechnology

1. If bacterial cells are transformed with a mixture of linear and circular molecules resulting from a ligation reaction designed to produce a recombinant molecule

Answer & Solution

Answer & Solution

3. Determine the correctness or otherwise of the following Assertion [A] and the Reason [R]. Assertion [A]: Dam methylase protects E. coli DNA from phage endonucleases. Reason [R]: E. coli Dam methylase methylates the adenosine residue in the sequence "GATC".

Answer & Solution

4. The schematic of a plasmid with a gap in one of the strands is shown below: Which of the following enzyme(s) is/are required to fill the gap and generate a covalently closed circular plasmid? P. DNA ligase Q. Alkaline phosphatase R. DNA polymerase S. Polynucleotide kinase

Answer & Solution

Answer & Solution

6. cDNA made from the mRNA of an organism was used to make a cDNA library in a vector that allows the expression as a fusion with a reporter tag. What percentage of the cDNA clones is likely to give rise to correct gene products?

Answer & Solution

7. Commonly used reporter gene in plant expression vectors is

Answer & Solution

8. EcoRI restriction sites on a 10kb DNA fragment are shown below Upon partial digestion, what are the lengths (in kb) of all the possible DNA fragments obtained?

Answer & Solution

9. What are the experimental steps needed for screening an expression library for clone encoding a protein X that has been isolated and purified? P. mRNA isolation Q. Antibody preparation R. Cloning into an appropriate vector S. Western blotting on transferred plaques

Answer & Solution

10. The basis for blue-white screening with pUC vectors is

Answer & Solution

1.
If bacterial cells are transformed with a mixture of linear and circular molecules resulting from a ligation reaction designed to produce a recombinant molecule

3.
Determine the correctness or otherwise of the following Assertion [A] and the Reason [R].
Assertion [A]: Dam methylase protects E. coli DNA from phage endonucleases.
Reason [R]: E. coli Dam methylase methylates the adenosine residue in the sequence "GATC".

4.
The schematic of a plasmid with a gap in one of the strands is shown below:
Which of the following enzyme(s) is/are required to fill the gap and generate a covalently closed circular plasmid?
P. DNA ligase
Q. Alkaline phosphatase
R. DNA polymerase
S. Polynucleotide kinase

6.
cDNA made from the mRNA of an organism was used to make a cDNA library in a vector that allows the expression as a fusion with a reporter tag. What percentage of the cDNA clones is likely to give rise to correct gene products?

7.
Commonly used reporter gene in plant expression vectors is

8.
EcoRI restriction sites on a 10kb DNA fragment are shown below
Upon partial digestion, what are the lengths (in kb) of all the possible DNA fragments obtained?

9.
What are the experimental steps needed for screening an expression library for clone encoding a protein X that has been isolated and purified?
P. mRNA isolation
Q. Antibody preparation
R. Cloning into an appropriate vector
S. Western blotting on transferred plaques

10.
The basis for blue-white screening with pUC vectors is