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.
Those are the major characteristics of vertebrates. Invertebrates. Invertebrates are simply the animals without a backbone. Invertebrates are a large group of animals that consist of more than 97% of all the animal species with a broad collection of animals including many Phylas and Subphylas. Vertebrates have a backbone with a spinal cord, whereas invertebrates do not. â¢ The diversity is exceptionally high among the invertebrates compared to vertebrates. â¢ Vertebrates are always bilaterally symmetrical, while invertebrates could show either bilateral or radial symmetry.