Development of Female Gametophyte

Development of female gametophyte, also known as the embryo sac, occurs within the ovule of the flower. This process involves several key stages that ultimately lead to the formation of the female gamete, the egg cell, which is essential for sexual reproduction in plants.

Megasporogenesis
- Megasporogenesis is the first stage in the development of the female gametophyte.
- It involves the formation of megaspores from a single megasporocyte within the ovule.
- Typically, only one of the four megaspores produced survives and develops further.

Formation of Female Gametophyte
- The surviving megaspore undergoes three rounds of mitotic divisions to form eight nuclei.
- These nuclei are then arranged in a specific pattern to form the mature embryo sac.
- The embryo sac consists of seven cells, including the egg cell, two synergids, three antipodal cells, and one central cell with two polar nuclei.

Fertilization
- Fertilization occurs when a pollen grain lands on the stigma of the flower and grows a pollen tube to reach the ovule.
- The two sperm cells within the pollen tube are released into the embryo sac.
- One sperm cell fuses with the egg cell to form the zygote, while the other sperm cell fuses with the two polar nuclei to form the endosperm.

Seed Development
- The zygote develops into an embryo, which will eventually grow into a new plant.
- The endosperm provides nutrients to the developing embryo.
- The ovule matures into a seed, containing the embryo, endosperm, and seed coat.

In conclusion, the development of the female gametophyte is a crucial process in plant reproduction, ensuring the formation of seeds for the next generation.