Germination of pollen on stigma.[Diagram drawn and annotated with the following points will also be considered]
- Stamen is the male reproductive part and it produces pollen grains.
- The ovary contains ovules and each ovule has an egg cell.
- The pollen needs to be transferred from the stamen to the stigma.
- If this transfer of pollen occurs in the same flower, it is referred to as self-pollination./ On the other hand, if the pollen is transferred from one flower to another, it is known as cross-pollination.
- After the pollen lands on a suitable stigma, it has to reach the female germ-cells which are in the ovary. For this, a tube grows out of the pollen grain and travels through the style to reach the ovary/Figure ·The male germ-cell produced by pollen grain fuses with the female gamete present in the ovule.
- This fusion of the germ-cells or fertilisation gives the zygote.
- After fertilisation, the zygote divides several times to form an embryo within the ovule.
- The ovule develops a tough coat and is gradually converted into a seed. The ovary grows rapidly and ripens to form a fruit.
- Meanwhile, the petals, sepals, stamens, style and stigma may shrivel and fall off.
