Question

Sporopollenin is deposited on the wall of pollens then how does a pollen tube can
emerge?
Why are PMC and MMC so important for gamete production in plants? Explain

Answer 1

1. The exine layer of the pollen grain contains sporopollenin, a substance that is chemically very stable. The deposition of sporopollenin is not uniform, giving rise to gaps in the exine layer called the germ pores. The intine grows out from these germ pores to form the pollen tube.

2. The pollen mother cell or microspore mother cell undergoes meiosis to form the male gametes called the pollen grains. The megaspore mother cell similarly undergoes meiosis to form the female gamete. The fusion between the male and the female gamete results in the formation of the zygote. Thus, both pollen mother cell and megaspore mother cell are important for reproduction in angiosperms.