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Pollen grains develop indiscrmiinately once they land on the stigmas. The discrimination for fertilization process arises when the angiosperm production occurs on the basis of compatibility, allowing only the pollen grains from appropriate species that are of the right shape to fertilize them. It can therefore be deducted that the growth of the pollen grains is indiscriminate and the 0vules choose the right ones that can fertilize them
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