The development of the embryo sac in flowering plants in the ovule of the ovary occurs as a result.

The embryo sac is formed as a result of the division by meiosis of the cells of the sporogenic tissue of the ovule of the pistil. As a result of meiosis, 4 haploid spores are formed, one of which is megaspores (macrospores), the other three spores die off (their function: uniform distribution of genetic material). Then the macrospore divides three times by mitosis, forming 8 haploid nuclei (cells). These cells make up the eight-core embryo sac. The two central nuclei merge to form a diployd central cell.