0.388 Hope this helped let me know if it was wrong :)
Answer:
The genetic variations that are best suited for their enviornment
Explanation:
Those that are not well suited for their environment will die off, leaving only the ones that are suited for it. This species will slowly take hold until the species has adapted and become a completely different one.
The respiratory and circulatory systems bring oxygen and nutrients to the cells. The respiratory and circulatory systems work together to maintain homeostasis. The respiratory system moves gases into and out of the blood.
<span>Bone marrow which is located <span>within the spongy or cancellous portions of bones is the essential site of new blood cell production or hematopoiesis. Bone marrow contains stem cells which able to differentiate into specialized cell types. People with diseases like blood cancers, such as leukaemia and lymphoma, sickle cell anaemia, and other rely on bone marrow transplantation to survive.</span></span>