A dominant allele is found in a population with a frequency of 0.8. As the environment begins to change, the dominant allele is not favored. Scientists find that the frequency of the dominant allele decreases by half each generation. What are the allele, genotype, and phenotype frequencies before and one generation after the population begins to change? Is Hardy-Weinberg equilibrium maintained?

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.