UPSC Prelims 2019 Q96: Science & Technology – Biotechnology & Genetics
- (a) 1, 2 and 4
- (b) 2 and 3
- (c) 1 and 3
- (d) 1 and 4 only
Answer: (a) 1, 2 and 4
Explanation
RNA Interference (RNAi): Applications
| Statement | Claim | Verdict | Detail |
|---|---|---|---|
| 1 | Used in gene silencing therapies | TRUE | RNAi's core mechanism = small RNAs (siRNA, miRNA) silence specific genes by binding mRNA. First siRNA drug: Patisiran (2018) for hATTR amyloidosis. |
| 2 | Used in cancer therapies | TRUE | RNAi silences oncogenes or drug-resistance genes; multiple RNAi anticancer drugs in trials. |
| 3 | Used in hormone replacement therapies | FALSE | Hormone replacement uses synthetic hormones (estrogen, testosterone), not RNAi. |
| 4 | Used to produce virus-resistant crops | TRUE | RNAi-based transgenic crops silence viral RNA - e.g. RNAi-resistant papaya (PRSV), RNAi-resistant tomato/soybean varieties. |
Statements 1, 2 and 4 are correct. Answer: (a) 1, 2 and 4.
Answer: (a) 1, 2 and 4.
Why each option is right or wrong
- (a) CORRECT. RNAi is used for gene silencing therapies (S1), cancer therapies (S2), and virus-resistant crops (S4). It is NOT used for hormone replacement (S3).
- (b) Incorrect. Hormone replacement doesn't use RNAi.
- (c) Incorrect. Virus resistance in crops is a key RNAi application.
- (d) Incorrect. Cancer therapy is also a key RNAi application.
Key point
RNAi: Gene silencing therapy (Patisiran 2018), cancer treatment (oncogene silencing), virus-resistant crops (papaya, tomato). NOT hormone replacement.
Remember
RNA interference (RNAi) technology is used for developing gene silencing therapies (S1), treatment of cancer (S2), and producing virus-resistant crops like PRSV-resistant papaya (S4). It is NOT used for hormone replacement therapies. Fire and Mello won the 2006 Nobel Prize for the discovery of RNAi.
Common mistakes
- Confusing RNAi with mRNA vaccines - both are RNA tech but different mechanisms.
- Assuming RNAi is only crops - therapeutic RNAi has grown massively since Patisiran.
- Not knowing Fire and Mello won 2006 Nobel Prize for discovering RNA interference in C. elegans.
Exam tip
RNA-based technologies: (i) RNAi - siRNA/miRNA silencing (Patisiran, Givosiran). (ii) mRNA vaccines - Pfizer, Moderna COVID vaccines. (iii) Antisense oligonucleotides (ASOs) - Nusinersen (Spinraza). (iv) CRISPR RNA guides - gene editing. (v) RNA aptamers - biosensors, drugs.
Sources
- NCERT Class 12 - Biology (Biotechnology chapters)
- Nature - Review articles on therapeutic RNAi and Patisiran approval