With reference to reproduction in plants, the "Double fertilisation" explains:

Answer: [A] how each single pollen grain is able to produce twin sperm cells

In Angiosperms plant reproduction, two structures are created: a zygote and the endosperm. A zygote will grow and develop into an embryo, or baby plant.The process of single pollen grain producing two sperm cells with one combining with egg to form a zygote and other to form endosperm is called double fertilization.

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