The mantle is the layer of the Earth that makes up most of Earth's mass. The mantle is a thick layer of hot rock that surrounds the hot, liquid, outer core. The mantle is below the crust and above the outer core.
Increase
Decrease
Stays the same
Stays the same
Whenever the sperm and the egg combine, it is possible for one or the other to not split properly and bring 2 of the chromosomes instead of just 1