Question

Draw a diagram of the mature embryo sac of an angiosperm and label the following parts in it.
-Filiform Apparatus
-Synergids
-Central cell
-Egg cell
-Polar nuclei
-Antipodal

Answer 1

Hint: Embryo sac is the female gametophyte of the seed-bearing plants which is present in the ovule of the plant. It contains an egg cell from which the embryo plant develops after fertilization (sexual reproduction).

Complete answer:
The ovule of the cell contains 3 layers the first layer is called the integument, the middle one is the nucellus (the remnant of the megasporangium) and the last is the embryo sac or the female gametophyte. The embryo sac has two ends, the micropylar end and the chalazal end. The sac contains six haploid cells and two haploid nuclei.

Parts of mature embryo sac of angiosperms:
-Egg apparatus: There is an egg cell present at the micropylar end of the embryo sac along with two Synergids and a filiform apparatus. These three cells together form an egg apparatus. Synergids help in guiding the pollen tube in the embryo sac. The egg cell after fertilization develops into a plant embryo.
-Antipodal cells: There are three cells present at the chalazal end called the antipodal cells.
-Polar nuclei: There is one nucleus from all the ends called the polar nuclei. They together form a central cell. They form endosperm on the fusion with male gametes and hence the phenomenon triple fusion occurs.

Note: The embryo sac in the angiosperms is a 7-celled and 8-nucleate structure. It contains a 1-egg cell, 2-synergids, 3-antipodal cells, and a central cell which contains 2 polar nuclei enclosed together. As the central cell contains 2 nuclei enclosed in a membrane so it is a 7-celled and 8-nucleate structure.