Double fertilization in flowering plants

Double fertilization in flowering plants

• Double fertilization is a complex fertilization mechanism of flowering plants or angiosperms. It involves the fusion of a sperm cell with an egg cell to form the zygote (which develops into the embryo) and the fusion of a second sperm cell with the central cell to form the primary endosperm nucleus (which develops into the endosperm, a nutrient tissue).

Steps in double fertilization:

1. Pollination: Pollen grains land on the stigma.
2. Pollen tube germination: A pollen tube grows down the style towards the ovule.
3. Sperm delivery: Two sperm nuclei travel down the pollen tube. One sperm fuses with the egg cell, and the other fuses with the central cell.
4. Fertilization: The fusion of sperm and egg creates a zygote. The fusion of the second sperm and the central cell creates the endosperm.
5. Development: The zygote develops into an embryo, and the endosperm develops into a nutritive tissue for the embryo.

Answer: Double fertilization involves the fusion of one sperm nucleus with the egg cell and another sperm nucleus with the central cell.