Integumentary system I believe
<span>A. Stimulus is the term used to describe what causes organisms to react to their environment. Stimulus is something that can provoke organisms to respond to the world around them. For example, if you put your hand on the stove, the stove is going to be the stimulus for you to get burned and move your hand from it because it will be to hot - that is going to be your reaction to the stimulus. Camouflage is a type of hiding mechanism, parasites are organisms, and homeostasis is equilibrium in an organism. </span>
Answer:
A
Explanation:
cells divide by mitosis hope this helps
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.
Erosion of sand n dirt and it ca cause sinkholes
