Question

My question is related to transportation topic under chapter 1 life processes and the question is if human need blood for transportation of oxygen for oxidation in cells where do this blood comes from is it in fixed amount since birth or generated and if generated then how

Answer 1

Blood is produced by our bone marrow.

Our bone marrow produces blood cells, called red blood cells, platelets, and white blood cells. Inside the marrow, blood cells start off as young, immature cells called stem cells. Once they develop, blood cells do not live for a long time inside our bodies