Skin in humans is Polygenic if A B C and D all promote skin pigment

answer: "circumcision is a common procedure in which the skin covering the tip of the penis is surgically removed."

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.

the answer to you question is   jet streams

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands