السؤال 106

Wind-pollinated plants release enormous quantities of pollen. Which explanation of that quantity is correct?

Every grain becomes a seed, so more grains means more seeds
The extra grains feed the insects that visit the flower
Wind pollen is heavy, so most of it drops straight to the ground
Only a tiny fraction of the lightweight grains reaches a stigmaالإجابة الصحيحة

الشرح

Air carries grains in every direction with no aim whatever, so the chance that any one grain settles on a suitable receiving surface is tiny, and the plant compensates by releasing far more than it could ever need. Equating grains with seeds confuses the delivery vehicle with the result, since a grain contributes to a seed only if it happens to arrive and fertilisation then follows.

الشرح

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