I'm pretty sure its because the sun is farther away from earth so C
It is transplanted routinely to treat a variety of blood and bone marrow diseases, blood cancers, and immune disorders. More recently, stem cells from the blood stream (called peripheral blood stem cells) and umbilical cord stem cells have been used to treat some of the same blood-based diseases
Because it carries a lot of blood to the arteries
4. Gene Pool is not a mechanism, thus your answer!
