Distribution of the cells within the embryo sac:-

• 3 cells are grouped together at the micropylar end and constitute the egg apparatus.
• The egg apparatus consists of 2 synergids and one egg cell.
• The synergids have special cellular thickenings at the micropylar tip called filiform apparatus. It helps to guide the pollen tubes into the synergid.
• Three cells are at the chalazal end and are called the antipodals.
• The large central cell has two polar nuclei.
• Thus, a typical mature angiosperm embryo sac is 8-nucleate and 7-celled.