megagametophyte उदाहरण वाक्य

उदाहरण वाक्य

1. In gymnosperms the megagametophyte consists of several thousand cells and produces one to several archegonia, each with a single egg cell.
2. In angiosperms, the megagametophyte is reduced to only a few nuclei and cells, and is sometimes called the embryo sac.
3. The megagametophyte develops within the megaspore of extant seedless vascular plants and within the megasporangium in a cone or flower in seed plants.
4. Megagametophytes and microgametophytes protruding through sporangium wall; megagametophytes floating on water surface with archegonia directed downward; microgametophytes remaining fixed to sporangium wall.
5. Megagametophytes and microgametophytes protruding through sporangium wall; megagametophytes floating on water surface with archegonia directed downward; microgametophytes remaining fixed to sporangium wall.
6. This process involves the joining of a female gametophyte ( megagametophyte, also called the embryo sac ) with two male gametes ( sperm ).
7. After pollination, a tube grows from the pollen through the stigma into the ovary to the ovule and two sperm are transferred from the pollen to the megagametophyte.
8. Embryo and megagametophyte are soft and translucent at first; later the endosperm becomes firm and milky white, while the embryo becomes cream-colored or light yellow.
9. This double fertilization is unique to flowering plants, although in some other groups the second sperm cell does fuse with another cell in the megagametophyte to produce a second embryo.
10. The microgametophyte  a pollen grain which has germinated from a microspore  is employed for dispersal, only releasing its desiccation-prone sperm when it reaches a receptive megagametophyte.