Question

Which of the following options is a correct match of phenomenon and its explanation?
A. Reverse Transcription PCR - Many copies of a DNA sequence.
B. Central dogma - RNA - DNA - Protein - RNA.
C. RNA silencing - Use of ds-RNA to stop the expression of ss-RNA.
D. Transcription - Process of formation of RNA and proteins.

Answer 1

Reverse transcription: It is the process in cells by which an enzyme called reverse transcriptase makes a copy of DNA from RNA.
Central dogma: Central dogma involves two processes, transcription and translation. By these processes information flows into protein.
DNA $\to$ RNA $\to$ protein
RNA Silencing: RNA silencing is gene silencing effects by which gene expression is negatively regulated by non-coding RNAs.
Transcription: Transcription is a process by which particular segment of DNA is copied into RNA by the enzyme RNA polymerase.

Complete answer:
In this question, we have given four pairs which involves four processes. Reverse transcription, central dogma, RNA silencing and transcription. So, first we'll learn about these 4 processes.
Reverse transcription: It is the process called reverse transcription polymerase chain reaction, in cells by which an enzyme called reverse transcriptase makes a copy of DNA from RNA.
Central dogma: Central dogma involves two processes, transcription and translation. By these processes information flows into protein and it also says that central dogma is irreversible. By this process DNA converts into RNA and then protein.
DNA $\to$ RNA $\to$ protein
RNA Silencing: RNA silencing is gene silencing effects by which gene expression is negatively regulated by non-coding RNAs.
Transcription: Transcription is a process by which particular segment of DNA is copied into RNA by the enzyme RNA polymerase.
Our first option is Reverse Transcription PCR - Many copies of a DNA sequence. As we have already defined the process of reverse transcription, in which RNA forms DNA and by PCR, we can make multiple copies of DNA.
The next option is Central dogma - RNA - DNA - Protein - RNA. We already mentioned the sequence of central dogma, which is DNA- RNA - protein. So this pair is incorrect.
The next option is RNA silencing - Use of ds-RNA to stop the expression of ss-RNA. RNA silencing is a negative regulation of non-coding RNA. So, this option is wrong.
The last option is Transcription - Process of formation of RNA and proteins. Transcription is the process of formation of only RNA from DNA, not protein.

So, the correct option is A. Reverse Transcription PCR - Many copies of a DNA sequence.

Note:
In reverse transcription PCR two processes are involved: Reverse transcription and PCR. Reverse transcription is formation of DNA from RNA and PCR is polymerase chain reaction, by which large amounts of copies of RNA and DNA can be produced.