Diffusion is the net movement of fluid from area of higher concentration to lower concentration, resulting from the random movement.
From example, if you drop a red ink in a cup of water, the ink will slowly spread among the water, making the water red. This is because the red ink is very concentrated, so it moves to the other part of water to lower the ink concentration. When it reaches the point where whole cup of water is red, it reached equilibrium and there's no more net movement
"Recombination" and "Genetic drift" are the two main sources among the following choices given in the question that lead to increased genetic variation. The correct options among all the options that are given in the question are the third and the fourth options. I hope the answer has helped you.
<span>Mendel showed that the green-seed trait did not disappear but was only masked by breeding plants with only two alleles for the trait. After the cross of yellow seed, a small amount of offspring had green seeds. So, he concluded that the green-seed trait is masked by the dominant yellow-seed trait and that two alleles are necessary for green-seed trait to show up.</span>
