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Plant hormones and tissues
6 MDCAT Biology questions with answers and explanations.
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Which plant hormone speeds up fruit ripening?
- 1 Auxin
- 2 Ethene (ethylene)
- 3 Cytokinin
- 4 Gibberellin
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Correct answer: Ethene (ethylene)
Ethylene is a gas that triggers ripening, which is why a ripe banana can ripen fruit stored next to it.
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Gibberellins promote:
- 1 Stem elongation and seed germination
- 2 Seed dormancy
- 3 Closing of stomata
- 4 Leaf fall
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Correct answer: Stem elongation and seed germination
Gibberellins make stems grow longer and help seeds break dormancy and germinate.
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Which plant tissue gives mechanical support through thick, lignified walls?
- 1 Parenchyma
- 2 Collenchyma
- 3 Sclerenchyma
- 4 Epidermis
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Correct answer: Sclerenchyma
Sclerenchyma cells have thick, hard walls with lignin and give strength to the plant.
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Cytokinins mainly stimulate:
- 1 Cell division
- 2 Leaf fall
- 3 Dormancy
- 4 Fruit ripening
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Correct answer: Cell division
Cytokinins promote cell division and delay the ageing of leaves.
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Which hormone keeps seeds dormant and closes stomata during water stress?
- 1 Abscisic acid
- 2 Auxin
- 3 Gibberellin
- 4 Cytokinin
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Correct answer: Abscisic acid
Abscisic acid is the stress hormone of plants. It maintains dormancy and makes guard cells close the stomata.
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Meristematic tissue is responsible for:
- 1 Storage of food
- 2 Growth by cell division
- 3 Transport of water
- 4 Protection of the plant
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Correct answer: Growth by cell division
Meristems, at the tips of roots and shoots, contain cells that keep dividing.