Our topic for today is Sexual reproduction in flowering plants.
Let us learn about the male and female reproductive parts of flowering plants.
Stamen is the male reproductive part of the flower.
It consists of the anther and the filament.
The anther produces pollen grains.
Each matured pollen grain contains a tube cell consisting of a tube nucleus and two male gametes.
Carpel is the female reproductive part of the flower.
Top part of the carpel is called the stigma.
Stigma is supported by the style.
Base part of the carpel is the ovary.
Ovary contains one or more ovules.
Each ovule has a female gamete.
Flowers that contain both male and female reproductive parts are called bisexual flowers.
Hibiscus and rose are some examples of bisexual flowers.
Flowers that contain either male or female reproductive parts are called unisexual flowers.
Papaya and watermelon are some examples of unisexual flowers.
For fertilization to take place, pollen grains need to be transferred from the stamen to the stigma.
If the transfer of pollen grain takes place in the same flower, then it is called self pollination.
If the transfer of pollen grain takes place from one flower to another, then it is called cross pollination.
This transfer of pollen grains is done by wind, water, insects or animals.
After the pollen grain lands on the stigma, the tube cell produces a pollen tube through the style into the ovule.
The male gametes travel along with the tube nucleus through the pollen tube.
After they reach the ovule, one of the male gametes fuses with the female gamete leading to fertilization.
Fertilization leads to the formation of zygote.
The other male gamete fuses with the polar nuclei to eventually form endosperm.
The zygote divides multiple times to form an embryo within the ovule.
The endosperm provides nourishment to the embryo.
Eventually, the ovule develops and turns into a seed.