"In ovule, there is present nucleus(mass of cells) the wall of ovule form teguments of nucellus. in nucellus one cell differentiate and form 2 megaspores. in each of the megaspores formed further activity takes place to form embryo sac."

In ovule there is present nucellus(mass of cells) The integuments develop into the seed coat when the ovule matures in nucellus one cell differentiate and form 2n megaspore mother cell. This 2n mother cell undergoes meiotic division to form embryo sac."