Why is the ozone layer crucial to life on earth

The ozone layer protects humans and other forms off life from the dangerous UV Rays of the sun. Without the ozone layer humans would not exist

Cis correct i think

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.