Medical Definition of Zygote
Zygote: The cell formed by the union of a male sex cell (a sperm) and a female sex cell (an ovum). The zygote develops into the embryo following the instruction encoded in its genetic material, the DNA.
The unification of a sperm and an ovum to form a zygote constitutes fertilization.
Quick GuideStages of Pregnancy: 1st, 2nd, 3rd Trimester Images
Subscribe to MedicineNet's Pregnancy & Newborns Newsletter