Zygote, fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm). In the embryonic development of humans and other animals, the zygote stage is brief and is followed by cleavage, when the single cell becomes subdivided into smaller cells. zoom_in.
[edit on Wikidata] A melanocytic nevus (also known as nevocytic nevus) is a type of lesion that contains nevus cells (a type of melanocyte). Some sources equate the term mole with melanocytic nevus. Other sources reserve the term mole for other purposes. The majority of moles appear during the first two decades of a person's life, with about one in every 100 babies being born with moles.
Acquired moles are a form of benign neoplasm, while congenital moles, or congenital nevi, are considered a minor malformation or hamartoma and may be at a higher risk for melanoma. A mole can be either subdermal (under the skin) or a pigmented growth on the skin, formed mostly of a type of cell known as a melanocyte. melanocytic nevus (also known as  nevocytic nevus ) is a type of lesion that contains nevus cells (a type of melanocyte). Some sources equate the term mole with melanocytic nevus. Other sources reserve the term mole for other purposes.