HELP PLEASE
(Not really biology but still help)

Explain why in any given geographical region, women tend to have lighter skins( by 3-4% on average) than men?

What is called the "building block" of life?

Blood stem cells may develop into any kind of human blood cells. what kind of stem cells are blood stem cells? a. multipotent stem cells o b. totipotent stem cells o c. pluripotent stem cells o d. unipotent stem cells