NEETZoologyBiotechnology - Principles and Processes
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Two sets of primers are essential for the amplification of a double-stranded DNA segment during a Polymerase Chain Reaction (PCR). Reason (R): DNA polymerase catalyzes polymerization only in one direction, that is 5' 3' , on antiparallel template strands. In the light of the above statements, choos
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A).
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A).
- C(A) is correct but (R) is not correct.
- D(A) is not correct but (R) is correct.
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
Step-by-step solution
Assertion (A) is correct because PCR requires two sets of primers (forward and reverse) to amplify both strands of the target double-stranded DNA. Reason (R) is correct and provides the correct explanation for (A). The two strands of the template DNA are antiparallel. Since DNA polymerase can only add nucleotides in the 5' 3' direction, synthesis on the two template strands must occur in opposite physical directions. Therefore, one primer is required to bind to the 3' end of one template strand, and a second primer