The zygote soon begins to divide rapidly in a process called cleavage, first into two identical cells called blastomeres, which further divide to four cells, then into eight, and so on.
Similarly, other fertility techniques such as gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT) are also more likely to result in multiple gestations.
Identical twins represent the splitting of a single fertilized zygote (union of two gametes or male/female sex cells to produce a developing embryo) into two separate individuals.
Oocyst-A developmental stage of certain parasitic organisms, including those responsible for malaria and toxoplasmosis, in which the zygote of the organism is enclosed in a cyst.
After the sperm penetrates the egg, a zygote cell is formed, which is a critical cell containing DNA that composes the genetic information for the developing baby.
The genetic material of the sperm and egg then combine to form a single cell called a zygote and the germinal stage of prenatal development commences.
The zygote, the name for the sperm and egg once they have come together, will then make its way down to the uterus.
Fertilization.The formation of the zygote or egg-cell takes place usually by the fusion of the contents of two cells, and always includes, as -
This is in consonance with the facts already mentioned that zoospores germinate forthwith, and that the sexually-produced cell or zygote enters upon a period of rest.
Thus, although isogamy consists in typical cases of a union of naked motile gametes by a fusion which begins at the beaked ends, and results in the formation of an immotile spherical zygote surrounded by a cell-wall, in Leptosira it is noticeable that the fusion begins at the blunt end; in a species of Chlamydomonas the two gametes are each included in a cell-wall before fusion; and in many cases the zygote retains for some time its motility with the double number of cilia.