megagametophyte उदाहरण वाक्य

उदाहरण वाक्य

1. The genetic control of apomixis can involve a single genetic change that affects all the major developmental components, formation of the megagametophyte, parthenogenesis of the egg cell, and endosperm development.
2. 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.
3. In flowering plants, double fertilization occurs, which involves two sperm fertilizing the two gametes inside the megagametophyte ( the egg cell and the central cell ) to produce the embryo and the endosperm.
4. Considerable confusion has resulted because diplospory is often defined to involve the megaspore mother cell only, but a number of plant families have a multicellular archesporium and the megagametophyte could originate from another archesporium cell.
5. Fossil lycopod megaspores reaching 1 cm in diameter, and surrounded by vegetative tissue, are known ( Lepidocarpon, Achlamydocarpon );  these even germinate into a megagametophyte " in situ ".
6. Within the megagametophyte one of the two sperm unites with the egg, forming a zygote, and the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process.
7. Each pollen grain accordingly may be seen as a male plant in its own right; it produces a sperm cell and is dramatically different from the female plant, the megagametophyte that produces the female gamete.
8. The egg producing gametophyte is known as a "'megagametophyte "', because it is typically larger, and the sperm producing gametophyte is known as a "'microgametophyte " '.
9. It also should be borne in mind that every sexually reproducing extant species of vascular plant actually has an alternation of generations; the plants we see about us generally are megagametophytes ( the embryo sacs in the ovules ).
10. These earliest ovules had the apical part of the nucellus exposed, from which there was a projection known as a lagenostome ( sometimes also called a salpinx ) that facilitated capture of the pollen and directed it down to the pollen chamber above the megagametophyte.