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eggclick to hear

Mature female reproductive cell produced by the ovary, which, after fertilization by a spermatozoon, enables the embryo to develop.
egg nucleus zona pellucida cytoplasm nucleolus corona radiata

nucleus click to hear

Organelle containing a cell’s genes and controlling its activities.

zona pellucida click to hear

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

Clear gelatinous substance surrounding the various cellular structures.

nucleolus click to hear

Small spherical body located inside the nucleus, within which the ribosomes, or protein-synthesizing structures, are produced.

corona radiata click to hear

Collection of granular cells that forms a protective crown around the egg.