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:
Spores are used by groups of ancient plants and fungi in one stage of their reproduction. ... Spores grow into intermediate plants called gametophytes. Neither of these groups of plants produces flowers. Pollen is used by flowering plants to fertilize seeds.
Explanation:
Answer:
Direct contact.
Explanation:
Since it was spread through facial tissue, physical contact is needed.
Hope this helps! :)
Answer:
3- As cells get larger, the volume increases more than the surface area
Explanation:
As a cell develops, it grows larger and extends the cell membrane. Sadly, the volume rises greater than that of the surface area, and therefore the relative surface area usable to transfer resources to a unit cell volume declines gradually.
