A zygote (from Greek ζυγωτός zygōtos joined or yoked, from ζυγοῦν zygoun to join or to yoke), is an eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information necessary to form a new individual. In multicellular organisms, the zygote is the earliest developmental stage.