Question

Explain the process of fertilization.

Answer 1

Process of fertilization in humans:

1. Formation of zygote by union of sperm and ovum is called as fertilization.
2. Fertilization is internal in humans. Semen is ejaculated in vagina during copulation.
3. Sperms, in the numbers of few millions, start their journey by the route of vagina – uterus – oviduct.
4. One of those few million sperms fertilizes the only ovum present in the oviduct.

Process of fertilization in plants:

1. Stigma becomes sticky during pollination.
2. The pollen grain germinates over the stigma and gives rise to pollen tube.
3. Pollen tube carries two male gametes which are released near egg cell present in the embryo sac.
4. One male gamete fuses with a female gamete giving rise to zygote. The second male gamete fuses with two polar nuclei giving rise to endosperm. This is called as double fertilization.