Answer to Question #157823 in Zoology for Bharat khandare

Question

Describe sexual reproduction in plant

Answer 1

Pollen grains are produced inside the anther through the process of meiosis in microspores mother cells (microsporogenesis). Pollen grains are also called the male gametophyte and they contain a tube nucleus and two male gametes.

Inside the ovule megaspore mother cell undergoes meiosis to make a 7-celled-8-nucleated gametophyte. It has two synergids, one egg cell, one central with two polar nucleic and three antipodals.

During pollination, pollen grain is transferred to the stigma from the anther.

Pollen grain germinates to produce the pollen tube which carries two male gametes to the female gametophyte via the style.

The two male gametes are released in one of the synergids.

One of the male gametes fuses with the egg cell forming the zygote. This is called syngamy.

The other male gametes fuses with the polar nucleic of central cell and forms triploid primary endosperm nucleus.

This is called triple fusion.

The event of triple fusion and syngamy is called double fertilization.The zygote develops into an embryo and the primary endosperm nucleus forms the endosperm.