Explanation

In isolecithal eggs, yolk is uniformly distributed (e.g., mammals). In centrolecithal eggs, yolk is in the centre of the egg (e.g., insects). In polyleithal eggs, yolk is in patches, (e.g., insects) and in telolecithal eggs, yolk is concentrated at one of the egg (e.g., frog, birds). Eggs of human being are microlecithal and isolecithal.