Question
Biology Question on The Female Reproductive System
Layers of an ovum from outside to inside is
corona radiata, zona pellucida & vitelline membrane
zona pellucida, corona radiata & vitelline membrane
vitelline membrane, zona pellucida & corona radiata
zona pellucida, vitelline membrane & corona radiata
corona radiata, zona pellucida & vitelline membrane
Solution
The mature ovum or a female gamete is spherical in shape. Its cytoplasm is called ooplasm containing large nucleus. The cytoplasm is enveloped by cell membrane (plasma membrane). The membrane forming the surface layer of an ovum is called the vitelline membrane. The plasma membrane of the ovum is surrounded by inner thick, non cellular zona pellucida; probably secreted by the follicular cells and outer very thick cellular corona radiata. The latter is formed of radially elongated follicular cells.