Adeer is born with the ability to smell predators better than the other deer in its population. as a result, this deer has several seconds of warning every time wolves or other predators attack. this trait may be selected by natural selection because it increases the deer's

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.