In flowering plants, the megagametophyte (also referred to as the embryo sac) is much smaller and typically consists of only seven cells and eight nuclei. This type of megagametophyte develops from the megaspore through three rounds of mitotic divisions.t consists of three parts: The integument(s) forming its outer layer(s), the nucellus (or remnant of the megasporangium), and female gametophyte (formed from haploid megaspore) in its center. The female gametophyteâspecifically termed a megagametophyte âis also called the embryo sac in angiosperms.
Late winter or early spring is the best time to begin spraying an apple tree. Using horticultural oil spray helps to destroy any insects and their eggs on the tree before new growth begins.
The best time to spray for tomato pests is in the morning, when bugs are still relatively sluggish and easy to spot. Coat the entire plant with the solution, and concentrate on the undersides of leaves or areas with heavy infestations.