Structure:
* Seven cells: The mature embryo sac contains seven cells with a total of eight nuclei.
* Egg cell: The egg cell is one of the cells in the embryo sac and is the female gamete. It is the one that will be fertilized by the male gamete from the pollen to form the zygote.
* Two synergids: These cells are located next to the egg cell and help guide the pollen tube to the egg cell. They also secrete substances that attract the pollen tube.
* Central cell: This cell contains two polar nuclei, which will fuse with a sperm nucleus from the pollen to form the endosperm, a nutritive tissue for the developing embryo.
* Three antipodal cells: These cells are located at the opposite end of the embryo sac from the egg cell and their function is not entirely understood. They may play a role in nutrient transport or may be vestigial.
Function:
* Female gametophyte: The embryo sac represents the female gametophyte generation in the flowering plant life cycle.
* Fertilization: It houses the egg cell, which is the female gamete, and the central cell, which contributes to the formation of the endosperm.
* Embryo development: After fertilization, the zygote develops into the embryo, and the endosperm provides nutrients for the developing embryo.
In summary, the embryo sac is a crucial structure within the ovule, responsible for housing the female gamete and contributing to fertilization and the development of the embryo and endosperm.
