The results will most likely be valid because the scientists kept getting the same results after REPEATED experiments. If they just conducted one experiment then they would not have been sure if what happened was a fluke or if another thing would happen after another experiment.<span />
A population that has been isolated, especially a smaller one, could have a high level of homozygosity and therefore not a lot of genetic variation. Gene flow between such populations can increase the level of heterozygosity, and therefore up genetic variation.
D. the <span>stomata close to preserve water and gas exchange decreases.</span>
