B.https://www.mansfieldct.org/Schools/MMS/staff/hand/genNaturalselection06.htm this is where I got my source.
Tge system that coirdinate and send message to the body is the nervous system
Answer:
The correct answer is: geography and UV radiation.
Explanation:
Skin variation occurred thanks to evolution, and was driven as a consequence of the geographical location of different populations of humans.
The humans that lived in hot and sunny places, closer to the equator, where much more exposed to the sun's ultraviolet radiation. In order to survive the amount of UV lights that they were exposed to, new humans in those regions were being born with a darker skin tone, which was rich in melanin (a brown pigment that protects us from the sun radiation).
Contrary to these humans that lived in the tropical areas, the humans that populated the areas that were closer to the poles, developed much lighter skin as a result of lower amounts of melanin in their skin. Since sun exposure in the poles is very limited, humans needed to receive as much as they could for the production of Vitamin D, and thus, their skins got lighter and less protected.
Answer - C. Bodies of water would freeze from the bottom up.
Reason - Since solid water aka ICE is denser than liquid.. Then we can kiss our penguins good buy cause the whole Earth will be submerge of water since the Arctic is made of ice and if it sank boom there goes for the planet and so as Antarctica.
The Answer Is A. Hope This Helps ;P