Center of flower has carpel, female reproductive organ. Stigma is where pollen lands Style is neck through which pollen tube grows Ovary has one or more ovules. Ovule has embryo sac that makes egg, and 2 polar nuclei. Details Ovule has diploid cell, which undergoes meiosis to form haploid cells. One haploid cell is megaspore.
Mitosis produces the embryo sac, the female gametophyte.
One of the cells in the embryo sac has 2 separate polar nuclei. Pollen sacs have diploid microsporocytes. Meiosis produces haploid microspores. Microspore mitosis produces male gametophyte, the pollen grain, with a tube cell and generative cell. Generative cell will divide into 2 nonmotile sperm.