Question

Choose the incorrect statement for the methodology of selection of molecules with mutant sequences.

(a) A vector is used which is having antibiotic resistance gene

(b) Apart from antibiotic resistance gene, a second antibiotic resistance gene is also present

(c) There are two mutagenic primers which are used

(d) The second strand synthesis is carried out by only one primer

The question was asked during an online exam.

My doubt stems from Mutagenesis using PCR and Recovery of Mutated Sequences in section Modifications and Mutagenesis of Genetic Engineering

Answer 1

The correct option is (d) The second strand synthesis is carried out by only one primer

The best I can explain: A vector is used which is having conventional antibiotic resistance and along with a second antibiotic resistance gene. The second gene is inactivated because of point mutation. Also, there are two mutagenic primers used. The first primer is used for directing the incorporation of mutation. The second primer makes the inactive gene inactive. Both the primers are used for second strand synthesis.