This set of Genetic Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Mutagenesis without PCR”.
1. Bisulphite ions are used to deaminate ________ residues in _______ DNA.
a) C, double stranded
b) C, single stranded
c) U, double stranded
d) U, single stranded
Explanation: Bisulphite ions are used to deaminate C residues in single stranded DNA. These C residues on deamination give U residues.
2. For mutagenesis without PCR, which of the following can be used as a template?
a) Single stranded DNA
b) Double stranded DNA
c) Circular DNA
d) Both single and double stranded DNA
Explanation: If mutagenesis is carried without PCR, both single and double stranded DNA can be used as a template. The single stranded DNA is obtained from filamentous phages and double stranded DNA is obtained from conventional vectors.
3. An oligonucleotide is synthesized which contains the mutation and the rest is _______ to the template DNA.
c) can either be complementary or non-complementary
d) not related
Explanation: The oligonucleotide is synthesized which contains the mutation and the rest of the sequence is complementary to the template DNA. And the oligonucleotide is allowed to anneal to the template DNA.
4. If the template is double stranded, they need to be separated before annealing of oligonucleotide.
Explanation: If the template is double stranded, then the two strands are separated before annealing of the oligonucleotide. This separation is done by heating or alkali denaturation.
5. Which of the following statement is incorrect for the synthesis of the second strand?
a) The oligonucleotide is acting as a primer for the synthesis of the second strand
b) DNA polymerase and dNTPs are added for synthesis
c) The polymerase should have 5’-3’ exonuclease activity
d) A polymerase having 5’-3’ exonuclease activity would degrade the primer that carries the mutant sequence
Explanation: The oligonucleotide is acting as a primer for synthesis of the second strand. DNA polymerase and dNTPs are added for synthesis and the polymerase should not have 5’-3’ exonuclease activity. If the polymerase is having exonuclease activity it would degrade the primer that carries the mutant sequence and the mutated portion is replaced by template DNA.
6. Once the double stranded molecule with the mutation is introduced into E. coli for replication, how many types of molecules are produced?
Explanation: Once the double stranded molecule with the mutation is introduced into E. coli for replication, there are basically two types of molecules produced after replication. One is the wild type molecule and the other is having mutated sequence.
7. How many sites can be mutated at a time?
Explanation: Many sites can be mutated at a time. For inducing more than one mutation, more than one mismatch are there in oligonucleotide to the target sequence.
8. Several different mutations can be induced at one site.
Explanation: Several mutations can be induced at one site. This is done by using a mixture of oligonucleotides which are having different nucleotides at the same position.
9. If mixed oligonucleotides are used, it is regarded as ______________
a) mixed mutagenesis
b) multiple mutagenesis
c) cassette mutagenesis
Explanation: Mixed oligomucleotides is the collection of those oligonucleotides which are having different nucleotides at the same position. This type of mutagenesis is called as cassette mutagenesis. It is a fast method for inducing multiple mutations.
10. It is easier to subclone a restriction fragment if it belongs to?
a) small gene
b) large gene
c) prokaryotic organism
d) eukaryotic organism
Explanation: If the target sequence belongs to a large gene, it is easier to sub-clone a restriction fragment from it and mutate the fragment. Chances of having unwanted mutations are also reduced.
Sanfoundry Global Education & Learning Series – Genetic Engineering.
To practice all areas of Genetic Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.
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