Page 5 - 2._Lesson_Notes-Sexual_Reproduction_in_flowering_Plants

 Fusion of male and female gametes is known as fertilization.

 In flowering plants after pollination, the pollens germinate on the stigma
surface of pistil. They absorb water, swell and germinate to produce pollen
tubes.
 The pollen tube passes through the style and moves towards the ovarian
cavity.

 Two non-motile male gametes are formed inside the tube during its growth
through the style.

 During the act of fertilisation, one male gamete fuses with the egg to form the
diploid zygote.

 The other male gamete fuses with the two polar nuclei to form the triploid
endosperm nucleus.
 The mechanism involving two acts of fertilisation in an embryo sac is called
double fertilisation.

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