Both of th <span>Both of these show the distribution of phenotypes. In directional selection, the distribution of phenotypes forms a "bell curve." Selection against one of the extreme phenotypes causes the distribution to "move" in one direction or the other. An example might be plants whose flower color is determined by incomplete dominance: white, pink, or red. Pink flowers may be the average phenotype, but if we start to remove red flowers from the population, the "mean" phenotype will be shifted toward white flowers. In disruptive selection, the average phenotype is selected against. This produces a "two-humped" bell-type curve, and the greater distribution is split between the two phenotype extremes. If we have the same type of incomplete dominance as mentioned in the previous paragraph, assume that the pink flowers are selected against. This means that the two "humps" shown in the distribution will be centered around the red and white phenotypes</span>
Somatic cells divide during meiosis, a process in which the genetic makeup or quantity of chromosomes in the daughter cells is maintained.
In sexually reproducing organisms, a kind of cell division known as meiosis results in a decrease in the number of chromosomes in gametes (the sex cells, or egg and sperm). Human body cells, also known as somatic cells, have two sets of chromosomes and are diploid (one from each parent).
A single cell splits twice during the meiosis process, resulting in four cells with half the original genetic material. These cells—sperm in men and eggs in women—are our sex cells.
I think it would be to exchange gases. When you think about it, plants in the past were always underwater. They didn't have any air. Now, they are on land and need to be able to exchange gases from the leaves to the roots.
