Draw and describe the structure of a matured embryosac of angiosperms.

Explanation

Detailed Answer:
At the micropylar end, three nuclei differentiate into two synergids and one egg cell. Together they are known as egg apparatus.
The synergids have special cellular thickenings at the micropylar tip. These are together called the filiform apparatus. It helps to guide the pollen tubes into the synergid.
Similarly, at the chalazal end, three out of the four nuclei differentiate as antipodal cells.
The remaining two cells (of the micropylar end and the chalazal end) move towards the center and are known as polar nuclei, which are situated in a large central cell.
Hence, at maturity, a typical mature angiosperm embryo sac (the female gametophyte) appears as a 7-celled structure, though it has 8-nucleate.