NEET Biology: Growth regulators-gibberellin Practice Questions
12 free multiple-choice questions on Growth regulators-gibberellin (Plant Growth and Development) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. Which physiological effect is associated with the presence of gibberellins in the growth zone of a plant?
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Correct answer: A — Promotion of cell elongation
The presence of GA promotes the elongation of cells, which is a key mechanism for overall plant growth.
Q2. The effect of gibberellin application on the growth of young shoot tissues is characterized by:
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Correct answer: A — Enhanced cell elongation
Gibberellin promotes cell elongation, leading to the stretching of internodes and overall shoot growth.
Q3. Gibberellins are stored in the seeds mainly in which form?
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Correct answer: C — Conjugated form
Gibberellins are stored in the seeds predominantly in their conjugated form, which is the active storage form.
Q4. Where is the primary site of synthesis for gibberellins in plants?
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Correct answer: C — Developing seeds and shoots
Gibberellins are synthesized mainly in the developing seeds and the shoot apex, which are active sites for growth.
Q5. If exogenous gibberellin is applied to a dormant seed, what is the immediate developmental response observed?
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Correct answer: D — Accelerated germination
Gibberellins are crucial for breaking dormancy and promoting the initiation of seed germination.
Q6. The growth-promoting effect of Gibberellins is mainly mediated by their interaction with which set of genes?
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Correct answer: B — GA-responsive genes
The physiological effects of Gibberellins are realized when they interact with and regulate the expression of specific GA-responsive genes in the plant cell.
Q7. In plants, gibberellins are primarily responsible for the elongation of which plant part?
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Correct answer: D — Stem
GA strongly influences cell elongation, leading to the significant elongation of the stem (internodes).
Q8. Which of the following is the primary source of gibberellins synthesized within the plant itself?
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Correct answer: C — Seeds
Gibberellins are synthesized in the apical meristems and are transported to growing tissues, primarily in the stem and internodes.
Q9. Gibberellins are primarily known for promoting which major growth process in plants?
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Correct answer: A — Stem elongation
Gibberellins (GA) are potent growth regulators whose primary role is to promote stem elongation and overall vegetative growth.
Q10. Gibberellin (GA) is a class of plant hormones primarily known for its role in which of the following processes?
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Correct answer: B — Seed dormancy and germination
Gibberellins are crucial regulators of seed dormancy and the process of germination, promoting the breaking of dormancy and subsequent growth.
Q11. Which of the following is the primary site where gibberellins are synthesized in plants?
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Correct answer: C — Meristems (apical and lateral)
Gibberellins are synthesized primarily in the apical and lateral meristems, where cell elongation and growth occur.
Q12. If a plant is provided with an adequate supply of Gibberellin, what is the expected macroscopic observation?
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Correct answer: A — Increased stem length
Since GA promotes cell elongation, an adequate supply will result in the observable growth and elongation of the plant stem.
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