UPSC Prelims 2012 Q65: Science & Technology – Biotechnology & Genetics
Other than resistance to pests, what are the prospects for which genetically engineered plants have been created?
1. To enable them to withstand drought
2. To increase the nutritive value of the produce
3. To enable them to grow and do photosynthesis in spaceships and space stations
4. To increase their shelf life
Select the correct answer using the codes given below:
- (a) 1 and 2 only
- (b) 3 and 4 only
- (c) 1, 2 and 4 only
- (d) 1, 2, 3 and 4
Answer: (c) 1, 2 and 4 only
Explanation
Why genetically engineered plants are made
| Purpose | Has it been done? | Example |
|---|---|---|
| 1. To enable them to withstand drought | Yes | Drought-tolerant maize and other crops |
| 2. To increase the nutritive value of the produce | Yes | Golden Rice, rich in vitamin A |
| 3. To enable them to grow and do photosynthesis in spaceships and space stations | No | No crop has been engineered for this |
| 4. To increase their shelf life | Yes | Flavr Savr tomato, which ripens slowly |
Other uses of genetic engineering in plants:
| Use | Example |
|---|---|
| Pest resistance | Bt cotton |
| Herbicide tolerance | Roundup Ready soyabean |
| Tolerance to salt, cold and heat | Crops for difficult soils |
| Less loss after harvest | Delayed ripening |
Answer: (c) 1, 2 and 4 only.
Why each option is right or wrong
- (a) Incorrect. Statement 4 is also true; plants have been engineered for longer shelf life.
- (b) Incorrect. Statement 3 on spaceships is false, and Statements 1 and 2 are left out.
- (c) CORRECT. Drought tolerance, better nutritive value and longer shelf life are real aims.
- (d) Incorrect. No plants have been engineered for photosynthesis in spaceships.
Key point
GM plants: pest resistance (Bt cotton), drought tolerance, nutrition (Golden Rice, vitamin A), shelf life (Flavr Savr tomato), herbicide tolerance.
Remember
Golden Rice = nutrition; Flavr Savr = shelf life.
Common mistakes
- Accepting the spaceship statement because it sounds futuristic.
- Forgetting Golden Rice as the standard example of better nutrition.
- Thinking GM crops are made only to resist pests.
Exam tip
Match each purpose to a known example. If no example comes to mind, as with spaceships, drop it.
Sources
- NCERT Class XII — Biology, Ch 12 (Biotechnology and its Applications)
- Food and Agriculture Organization — The State of Food and Agriculture: Agricultural Biotechnology