Q.56 Given below are two statements :
Statement I :
Many species of biennials and perennials are induced to flower by low temperature exposure
(0°C to 5°C) and the process is called vernalization.
Statement II :
Vernalization elongates the vegetative period and induces the plant to flower earlier.
In the light of the above statements, choose the correct answer from the options given below :
- Both Statement I and Statement II are true
- Both Statement I and Statement II are false
- Statement I is true but Statement II is false
- Statement I is false but Statement II is true
Statement I is true, but Statement II is false, as vernalization promotes flowering in response to cold exposure, but it shortens—rather than elongates—the vegetative phase to induce earlier flowering.
Statement Analysis
Statement I: Correct—vernalization accelerates flowering in many biennials (e.g., winter wheat) and perennials via prolonged cold (0-10°C, often 0-5°C as stated), ensuring proper timing after winter; the floral stimulus (vernalin) persists mitotically.
Statement II: Incorrect—vernalization shortens the juvenile/vegetative period, hastening the transition to reproductive flowering rather than extending it.
Option Breakdown
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Both true: Wrong; II wrongly claims vegetative elongation.
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Both false: Wrong; I accurately defines vernalization.
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I true, II false: Correct; matches precise biology.
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I false, II true: Wrong; I holds, II reverses the effect.
Introduction to Vernalization Low Temperature Flowering
Vernalization low temperature flowering ensures biennials and perennials like wheat bloom post-winter (0-10°C exposure), vital for GATE plant physiology; it creates epigenetic “memory” for competent flowering.
Vernalization Mechanism
Cold induces vernalin at meristems (shoot apex, embryos), shortening vegetative growth for earlier bloom under photoperiod cues; sites include young leaves.
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Accelerates flowering in temperate crops.
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Prevents premature spring germination.
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Enhances yield, cold resistance.
| Statement |
Accuracy |
Explanation |
| I |
True |
Cold (0-5°C) triggers flowering |
| II |
False |
Shortens vegetative phase |
GATE Q.56 Verdict
Statement I true, II false—vernalization hastens flowering by abbreviating vegetative time, not extending it.
