Embryonic Development of Egg and Yolk in Insects and Birds
In this article we will discuss about the embryonic development of egg and yolk in insects and birds. Egg: The eggs are generally spherical but eggs of insects are elongated and cylindrical. The eggs of some polychaetes, fishes and birds are oval in shape. The egg cells are covered by plasma membrane which is secreted by egg cytoplasm (ooplasm). The [...]