Main Page | See live article | Alphabetical index Main Page | See live article | Alphabetical index In biology, a zygote is the result of fertilization. That is, two haploid cells - usually (but not necessarily in some organisms) a male sperm cell and a female ovum or ovule - merge into a single diploid cell called the zygote. This cell undergoes multiple cell divisions in gametic and sporic meioses (see biological life cycles) to become an embryo. See also: pregnancy This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.