Zona pellucida

Definition

The zona pellucida is a thick, glycoprotein layer surrounding the plasma membrane of mammalian oocytes. It plays a crucial role in fertilization by allowing only sperm of the same species to bind and facilitates sperm penetration during the fertilization process.

Related terms

Oocyte: An immature egg cell in the ovary that can develop into an ovum after meiotic division.

Fertilization:

The process by which a sperm cell combines with an egg cell to form a zygote, marking the beginning of pregnancy.

Glycoprotein:

A molecule consisting of carbohydrate plus protein, essential for various biological processes including cell-cell recognition and signaling in fertilization