Question

____________ of mRNA takes place during the process of RNAi.

• A. Translation
• B. Silencing
• C. Transcription
• D. Splicing

Answer 1

The correct option is B Silencing

The primary purpose of the genetic material in an organism is to carry information in the form of codes for the synthesis of appropriate proteins.

DNA (deoxyribonucleic acid) is the genetic material in most of the organisms that carries these codes.

RNA (ribonucleic acid) plays an important role in the process of using these codes for protein synthesis, which is carried out in the following steps-

• Transcription
• Translation

Transcription: it is the process during which the genetic information is copied from one strand of the DNA to generate an mRNA which is also called heterogeneous RNA (hnRNA). It has both the exons (coding sequences) and introns (noncoding sequences). This is the primary transcript.

Splicing: The primary transcript undergoes a process called RNA splicing in eukaryotes, where the introns are removed, thus forming an mRNA ready for translation.

Translation: it is the process where the spliced mRNA with the codons for the amino acids, is translated into a polypeptide chain.

Silencing (of mRNA): if this transcribed mRNA is exposed to a complementary RNA strand, it will lead to the formation of a dsRNA (double-stranded RNA). Now, there is no possibility by which translation can take place, since this dsRNA is degraded by the enzymes. This mechanism where an RNA strand silences or stops the transcribed mRNA from being translated, can be correctly described as RNA interference (RNAi) or RNA silencing.