archegonium वाक्य

उदाहरण वाक्य

1. Each archegonium has a slender hollow tube, the " neck ", down which the sperm swim to reach the egg cell.
2. When the sporophyte has developed all three regions, the seta elongates, pushing its way out of the archegonium and rupturing it.
3. In these plants, the embryo begins its existence attached to the inside of the archegonium on a parental gametophyte from which the egg cell was generated.
4. These sporelings develop via an embryo stage from a fertilized egg inside an archegonium and depend on the gametophyte for their early stages of growth before becoming independent sporophytes.
5. The female organs are known as archegonia ( " sing . " archegonium ) and are protected by a group of modified leaves known as the perichaetum ( plural, perichaeta ).
6. Firstly, their gametophytes produce sperm and eggs in multicellular structures ( called'archegonia'), and fertilization of the ovum takes place within the archegonium rather than in the external environment.
7. Secondly, and most importantly, the initial stage of development of the fertilized egg ( the zygote ) into a diploid multicellular sporophyte, take place within the archegonium where it is both protected and provided with nutrition.
8. The inner wall of the archegonium lies in close contact with the " foot " of the developing embryo; this " foot " consists of a bulbous mass of cells at the base of the embryo which may receive nutrition from its parent gametophyte.
9. It is a short-lived and inconspicuous heart-shaped structure typically 2 5 millimeters wide, with a number of rhizoids ( root-like hairs ) growing underneath, and the sex organs : archegonium ( female ) and antheridium ( male ).
10. Two sperm nuclei from a pollen grain ( the microgametophyte ), rather than a single sperm, enter the archegonium of the megagametophyte; one fuses with the egg nucleus to form the zygote, the other fuses with two other nuclei of the gametophyte to form'endosperm', which nourishes the developing embryo.