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.
Listed below are a few points to keep in mind when purchasing apple trees: 1  The preferred type of tree for planting is a healthy, one-year-old whip that is approximately 4 to 6 feet tall and has a good root system. 2  A small tree with a good root system is more desirable than a large tree with a poor root system.