Q.42 Given below are two statements:
Statement I : Golden rice is a transgenic crop with enhanced levels of riboflavin (a precursor of vitamin A).
Statement II : To create golden rice, the genes used were isolated from daffodil and a bacterium.
In the light of the above statements, choose the correct answer from the options given below:
(1) Both Statement I and Statement II are true
(2) Both Statement I and Statement II are false
(3) Statement I is true but Statement II is false
(4) Statement I is false but Statement II is true
Golden rice transgenic crop addresses vitamin A deficiency via beta-carotene, not riboflavin, making Statement I false while Statement II holds true on daffodil and bacterial genes.
Question Breakdown
The query tests knowledge of golden rice as a transgenic crop engineered for nutrition. Statement I claims enhanced riboflavin (a precursor of vitamin A); Statement II notes genes from daffodil and bacterium.
Golden rice produces beta-carotene in endosperm, converted to vitamin A (retinol), targeting deficiency in rice-dependent areas.
Statement Analysis
Statement I: False
Riboflavin (vitamin B2) aids energy metabolism, not a vitamin A precursor—beta-carotene is. Golden rice boosts beta-carotene (provitamin A), yielding golden grains; 50g provides ~60% child RDA. Claiming riboflavin confuses B vitamins with carotenoids.
Statement II: True
Genes psy (phytoene synthase) from daffodil (Narcissus) and crtI (phytoene desaturase) from bacterium Erwinia uredovora create beta-carotene pathway in rice endosperm via Agrobacterium transformation.
Option Explanations
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(1) Both true: Incorrect; Statement I wrong on riboflavin.
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(2) Both false: Incorrect; Statement II accurate on gene sources.
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(3) I true, II false: Incorrect; I false, II true.
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(4) I false, II true: Correct answer.
Golden Rice Development
Engineered in 1990s by Potrykus and Beyer, Golden Rice 2 uses maize psy instead of daffodil for higher beta-carotene (up to 35 μg/g). Pathway: GGPP → phytoene → lycopene → beta-carotene via inserted enzymes.
| Aspect |
Detail |
| Target Nutrient |
Beta-carotene → Vitamin A |
| Genes |
Daffodil psy, bacterial crtI |
| Impact |
50%+ RDA from modest intake |
| Status |
Field-tested; regulatory hurdles |
Clinical trials confirm efficient conversion (3.8:1 beta-carotene to retinol). Ideal for GATE Life Sciences on plant biotech.
