Ovule: Structure, Types, and Embryo sac

Embryo sac and its Development
The first cell of the female gametophyte is the functional megaspore. It grows largely along the micropyle-chalazal axis and is mostly chalazal. The nucleus undergoes three mitotic divisions and forms eight nuclei. Out of the Eight nuclei, 4 are present at the micropylar end and 4 at the chalazal end. One nucleus from each group comes in the center to form 2 polar nuclei. The remaining three nuclei at the micropylar end make up the egg apparatus, whereas the remaining three nuclei at the chalazal end make up three antipodal cells. The mature female gametophyte or embryo sac is the entire structure with two polar nuclei, three antipodals, one egg, and two synergids. the Monosporic 8- nucleate embryo sac or polygonum type of embryo sac arises from a single megaspore and has 8 nuclei

Ovule: Structure, Types, and Embryo sac Read More »