Varicose veins seen in the superficial veins of the legs are unsightly and are often treated by surgical removal. However, even without these veins being present, the return of all blood toward the heart from the legs is not diminished. This is primarily because .

Dna overload will occur

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.

Dnaa living organsimcreation from organic chemicals