<span>New combinations of genes may be produced by </span>immigration, mutation and sexual reproduction. These new combinations are also called variations.
I think the most appropriate answer is A !!
as pyruvate is broken down into CO2 !
as C and D is out of options as there is no such event at all !
and NADH is not formed from glucose !
so I would like to suggest A !!!
Answer:
Skin serves as a protective barrier, a way to sense the world, and a layer that keeps nutrients and water inside the body. Four types of cells make up the skin, and they are produced mainly in the epidermis near the basement membrane. Keratinocytes contain structural keratin and make up the bulk of the epidermis.