Explain the process of fertilization in plants. (AS1)

a) The pollen grain reaches the stigma of the flower called pollination.

b) The pollen tube starts germinating, the pollen contains 2 cells- generative cell and a vegetative cell.

c) Both the cells travel through the pollen tube which leads them to the embryo sac.

d) The embryo sac is a 7 celled 8 nuclei structure.

e) One of the male gametes fuses with the female egg- called syngamy, while the other fuses with the 2 polar nuclei forming a triploid- called triple fusion.

f) Since 2 kinds of fertilization take place in a plant, it is also called double fertilization.

g) After fertilization, the triploid central cell develops into endosperm while the zygote develops into an embryo.