Answer:
a. 50%
Explanation:
<em>BRCA1 genes is a tumor supressor gene whose harmful mutation can cause hereditary breast ovarian cancer syndrome in both males and females. The BRCA actually stands for breast cancer.</em>
<em>Mutation in BRCA1 gene is heritable and every progeny of a carrier parent irrespective of the sex has a 50% chance of inheriting the trait from such parent, be it from the mother or the father.</em>
Hence, the correct option is a.
Answer:
Senior mothers are also under pressure to share food with their sons, so that they're able to reproduce as well. It also makes sense for these mothers to assist their sons because as the mothers grow older, they are increasingly related to whales in other, neighboring pods via their sons' calves.
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.
