Why do continents rise above the ocean floor?

This increase is linked to the continental crusts rising above the oceans. ... As Earth's land plates began to shift and move, less dense rock may have been forced upward, shaping the continents we see today on Earth's crust.

Explanation:

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.