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Why do seeds of small-seeded species usually require light as a germination cue?

ALight warms the soil enough to soften the coat
BLight signals that pollinators are already active
CLight means they lie near the surface they can reach
DLight triggers the enzymes that digest the endosperm
Answer & Solution
Correct answer: C. Light means they lie near the surface they can reach
1. The time a seedling takes to emerge depends partly on seed size. 2. Species with large seeds have enough food reserves to germinate deep below ground and still push the epicotyl to the surface. 3. Seeds of small-seeded species usually require light as a germination cue. 4. That requirement ensures they only germinate at or near the soil surface, where light is greatest. 5. If such a seed germinated too far below the surface, the seedling would run out of reserves before reaching sunlight. 6. So the cue is about depth, not about temperature or the timing of pollinators. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 32 "Plant Reproduction", section 32.2 Pollination and Fertilization_
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