Describe the parts of a mature angiosperm embryo sac. Mention the role of synergids.

In angiosperms the female gametophyte is called as embryo sac. The most common embryo sac is 7 celled and 8 nucleated polygonum type.
The embryo sac shows three main parts. These are
i) Egg Apparatus ii) Antipodals iii) Central cell.
i. Egg apparatus :
Three cells (one egg cell & two synergids) are grouped together at the micropylar end of embryo sac and constitute the egg apparatus. Synergids contains filiform apparatus.
Role of synergids : Absorption of nutrients from nucellus. Filiform apparatus guide the entry of pollen tube into synergid.
ii. Antipodals :
Three cells present in the chalazal end of embryo sac called as antipodals. These cells are short lived and smallest cells considered as vegetative cells of embryo sac degenerate before (or) after fertilization.
iii. Central cell : It is a largest cell of embryo sac. It has two polar nuclei often fuse in centre to form a single diploid secondary nucleus.