Erythropoiesis (from Greek 'erythro' meaning red and 'poiesis' meaning to make) is the process which produces red blood cells (erythrocytes).
Birds and mammals have the following characteristics in common: they are vertebrates, meaning they have an internal skeletonthey are warm-bloodedthey breathe using lungs, so â¦ have full respiratory systems they have circulatory systems. Most mammals give live birth, but there is a sub-group known as monotremes, which are the egg-laying mammals. 2  This group includes just the platypus and the echidna. 3  They are still mammals because, like all mammals, they feed their young on mothers' milk.
Mammals are easily distinguished from other animals and generally share the following characteristics: Fur: While some other animals may appear to have hair (e.g. some kinds of spiders), the presence of true fur is a unique mammalian characteristic. Air breathers: All mammals breathe air; even the ones that live in water must come to the surface to breathe.