Correct option (a) Reverse Transcription PCR - Many copies of a DNA sequence.
Explanation :
Reverse Transcription Polymerase Chain Reaction (RT-PCR) is a variant of Polymerase Chain Reaction (PCR), a laboratory technique commonly used in molecular biology to generate many copies of a DNA sequence, a process termed "amplification". In RT-PCR, however, an RNA stand is first reverse transcribed into its DNA complement (complementary DNA, or cDNA) using the enzyme reverse transcriptase, and the resulting cDNA is amplified using traditional PCR or Real-time PCR. Reverse transcription PCR (RT-PCR)is not to be confused with Real-Time Polymerase Chain Reaction (Q-PCR/qRT-PCR), RNA silencing (also called as post-transcriptional gene silencing PTGS) refers to a family of gene silencing effects by which the expression of one or more genes is down regulated or entirely suppressed by the introduction of an antisense (single stranded) RNA molecule. Transcription is the process of creating a complementary RNA copy of a sequence of DNA.
