Welcome to the Quiz!
This quiz contains 10 questions from a mix of 1 subtopics.
What is the primary benefit of phototropism for a plant?
to obtain nutrients and minerals
to anchor the plant in the soil
to maximise light capture for photosynthesis
to respond to physical contact
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What type of tropism occurs when shoots grow towards the light?
positive phototropism
negative phototropism
positive geotropism
negative geotropism
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What type of tropism is occurring when roots grow downwards?
positive geotropism
positive phototropism
negative chemotropism
negative hydrotropism
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Which plant hormone plays a central role in directing phototropism and geotropism?
cytokinin
auxin (IAA)
gibberellin
ethylene
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During negative phototropism and positive geotropism in roots, where does IAA become concentrated?
the upper side of the root
equally throughout the root
in the shoot tip
the lower, shaded side of the root
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What effect does the concentration of IAA have on the lower, shaded side of a root during negative phototropism and positive geotropism?
it inhibits cell elongation
it stimulates cell elongation
it causes the root to bend towards the light
it has no effect on cell elongation
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What is etiolation?
the rapid upward growth that takes place in a plant grown in the dark
the bending of a plant in response to touch
the bending of a plant towards the light
the bending of a plant towards gravity
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What hormone is responsible for the extreme elongation of internodes during etiolation?
gibberellin
auxin (IAA)
ethylene
cytokinin
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What type of tropism occurs when roots grow away from light?
positive geotropism
negative phototropism
positive phototropism
negative geotropism
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Explain the role of IAA in the control of positive phototropism in shoots.
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