Question

RNA interference involves:

• A. Synthesis of DNA and RNA using reverse transcriptase
• B. Silencing of specific mRNA due to complementary RNA
• C. Interference of RNA in synthesis of DNA
• D. Synthesis of mRNA from DNA

Hint:

RNAi = Gene Silencing Complementary RNA + Target mRNA \[ \Downarrow \] No Translation \[ \Downarrow \] No Protein Formation

Answer 1

The Correct Option is B

Concept: RNA interference (RNAi) is a natural cellular mechanism that regulates gene expression by preventing the translation of specific messenger RNA molecules. This process was used by scientists to develop genetically modified organisms resistant to pests and diseases. RNA interference works through complementary RNA molecules that bind to target mRNA and prevent protein synthesis.

Step 1: Understand the meaning of RNA interference.
The term RNA interference means: \[ \text{Interference with gene expression by RNA molecules} \] The process prevents a gene from expressing itself.

Step 2: Study the mechanism of RNAi.
A double-stranded RNA molecule enters the cell. The cell processes this RNA into small fragments. These fragments recognize complementary messenger RNA. \[ \text{Complementary RNA} \longrightarrow \text{Binds to mRNA} \]

Step 3: Observe what happens to the mRNA.
Once complementary RNA binds to the target mRNA:
• Translation is blocked
• mRNA may be degraded
• Protein synthesis stops Thus the gene becomes silent.

Step 4: Relate this to NCERT biotechnology applications.
RNA interference was used in the development of nematode-resistant tobacco plants. Scientists introduced genes producing complementary RNA. This complementary RNA silenced the parasite's essential genes.

Step 5: Select the correct option.
RNA interference specifically refers to: \[ \boxed{\text{Silencing of specific mRNA due to complementary RNA}} \]