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:
1) Homologous chromosomes are chromosomes that are the same in size and shape and control the same characteristics; occur in pairs in higher animals and plants
2) Internal fertilization is a mating pattern in which the male and female come close together, the male introduces the sperm into the body of the female, and fertilization occurs. It is practiced by mammals like goat, sheep etc
3) Pollination is the transfer of pollen from male to female cones in gymnosperms, or from anther to stigma in flowering plants. It is effected by insects, birds, bats and the wind.
4) Zygote is the result of fertilization in which two gametes have fused together; often simply called a fertilized egg.
I hope this help but the metalloids is gruop five if that what your asking if not i will answer the other question for you