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.
One of the main characteristics that is used to distinguish one class of animals from another is type of. skin covering. Mammals have hair or fur, birds have feathers, reptiles have dry scales, amphibians. have soft, moist skin, and fish have wet, slimy scales. Although each skin covering is useful in many ways, the focus of this information is how various colors and patterns help an animalâs chances for