1 Question Which trait—white flowers or purple flowers—is controlled by a dominant allele? Which is controlled by a recessive allele? How do you know? 2 Question In which generation are the parents purebred? In which generation are they hybrids?

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.