UPSC Prelims 2010 Q8: Science & Technology – Biotechnology & Genetics
- (a) The grains have been fortified with genes to provide three times higher grain yield per acre than other high yielding varieties
- (b) Its grains contain pro - vitamin A which upon ingestion is converted to vitamin A in the human body
- (c) Its modified genes cause the synthesis of all the nine essential amino acids
- (d) Its modified genes cause the fortification of its grains with vitamin D
Answer: (b) Its grains contain pro - vitamin A which upon ingestion is converted to vitamin A in the human body
Explanation
What "golden rice" is genetically engineered to do
Golden rice is one of the most well-known biofortification success stories in agricultural biotechnology.
| Option | Verdict | Reason |
|---|---|---|
| (a) Three times higher grain yield | Incorrect | Golden rice's engineering is not about yield; it targets a specific nutrient deficiency |
| (b) Contains pro-vitamin A, converted to vitamin A in the body | Correct | Golden rice is engineered to produce beta-carotene (pro-vitamin A) in its grains, which the human body converts into vitamin A, addressing vitamin A deficiency |
| (c) Synthesizes all nine essential amino acids | Incorrect | This is not golden rice's engineered trait; it is specifically about vitamin A, not amino acid completeness |
| (d) Fortified with vitamin D | Incorrect | Golden rice targets vitamin A, not vitamin D |
Golden rice facts:
| Point | Detail |
|---|---|
| Engineered trait | Beta-carotene (pro-vitamin A) in grains |
| Health target | Combat vitamin A deficiency, a major issue in rice-dependent diets |
| Mechanism | Body converts ingested pro-vitamin A into usable vitamin A |
Answer: (b) Its grains contain pro-vitamin A which upon ingestion is converted to vitamin A in the human body.
Why each option is right or wrong
- (a) Incorrect. Golden rice's modification is not about yield enhancement.
- (b) CORRECT. Golden rice's grains are engineered to contain pro-vitamin A (beta-carotene), converted to vitamin A in the body.
- (c) Incorrect. The modification targets vitamin A, not complete essential amino acid synthesis.
- (d) Incorrect. The targeted nutrient is vitamin A, not vitamin D.
Key point
Golden rice is engineered to produce pro-vitamin A (beta-carotene) in its grains, which the human body converts into vitamin A — addressing vitamin A deficiency, not yield, amino acids, or vitamin D.
Remember
Golden rice: engineered to contain pro-vitamin A (beta-carotene), converted to vitamin A in the human body.
Common mistakes
- Confusing golden rice's nutritional biofortification goal with a yield-enhancement trait.
- Mixing up the targeted nutrient (vitamin A) with other vitamins like vitamin D.
- Overstating the engineering as covering all essential amino acids, rather than a single specific nutrient.
Exam tip
Golden rice = pro-vitamin A (beta-carotene) biofortification, nothing about yield or amino acids. A frequently tested GM-crop fact.
Sources
- Xudong Ye et al. — "Engineering the Provitamin A (β-Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm", Science, vol. 287 (2000)
- World Health Organization — Micronutrient deficiencies: Vitamin A deficiency