egg![click to hear](/images/speaker.jpg)
Mature female reproductive cell produced by the ovary, which, after fertilization by a spermatozoon, enables the embryo to develop.
nucleus ![click to hear](/images/speaker.jpg)
Organelle containing a cell’s genes and controlling its activities.
zona pellucida ![click to hear](/images/speaker.jpg)
Fine granular coat composed of mucopolysaccharides covering the egg; it allows a single spermatozoon to penetrate the egg, which then becomes impermeable to others.
cytoplasm ![click to hear](/images/speaker.jpg)
Clear gelatinous substance surrounding the various cellular structures.
nucleolus ![click to hear](/images/speaker.jpg)
Small spherical body located inside the nucleus, within which the ribosomes, or protein-synthesizing structures, are produced.
corona radiata ![click to hear](/images/speaker.jpg)
Collection of granular cells that forms a protective crown around the egg.