What is natural selection? a process that selects variations that help with survival and that spreads the variations to more offspring

a process through which nature selects an individual within a population for extinction

a process that causes all populations to gradually increase in size

a process that causes random variations to appear in the offspring of every generation

Idk little ngr try paying attention in school and you would know ngr

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.