Overview
An egg (卵, amago) is a s a reproductive cell. Officially, it is called an ovum. Basically, all reproductive cells of sexually reproducing organisms are eggs, but those commonly referred to by this name are generally those produced by oviparous organisms (birds, reptiles, insects, fish and shellfish). Oviparous organisms generally lay eggs covered with an outer shell (which may be soft or hard) and are often large enough to be easily seen by the naked eye. In many cases, they are the largest single cells in the organism.