Metion the ploidy of the different types of cells present in the female gametophyte of an angiosperm.

Explanation

There is a characteristic distribution of the cells within the embryo sac. Three cells are grouped together at the microplar end and constitute the egg apparatus. The egg apparatus, in turn, consists of two synergids and one egg cell. The synergids have special cellular thickenings at the micropylar tip called filiform appartus, which play an important role in guiding the pollen tubes into the synergid. These cells are the chalazal and are called the antipodals. The large central cells as mentioned earlier, has two polar nuclei. Thus, a typical angiosperm embryo sac, at maturity, though 8-nucleate is 7-celled.