Laboratory technique used to make multiple copies of a DNA segment is:

Correct option is A

The correct answer is (a) PCR, which stands for Polymerase Chain Reaction. It is a molecular biology technique used to amplify a specific DNA segment, producing millions to billions of copies of a particular DNA sequence from a small initial sample.
�� Key Features of PCR:
· Developed by: Kary Mullis in 1983 (Nobel Prize in Chemistry, 1993)
· Function: Amplifies DNA exponentially through thermal cycling.
�� Steps in PCR:
1. Denaturation (94–96°C):
· Double-stranded DNA is heated to separate into single strands.
2. Annealing (50–65°C):
· Primers bind to specific target sequences on the single-stranded DNA.
3. Extension (72°C):
· Taq DNA polymerase synthesizes the new DNA strand by adding nucleotides.
These steps are repeated for 25–35 cycles, doubling the DNA with each cycle.
Explanation for Each Option
(a) PCR ✅
· Correct answer.
· Specifically designed to amplify DNA sequences rapidly and efficiently.
(b) Electrophoresis ❌
· Used to separate DNA fragments by size, not to amplify them.
(c) Recombinant DNA technology ❌
· Involves insertion of DNA fragments into vectors and host organisms for cloning or protein production, but is not used solely for amplification.