Our entire body is covered with a protective layer of epithelial cells. The layer of epithelial cells acts as the first line of defense against invaders from the exterior. Skin cells are constantly dying. Additionally, they are frequently damaged, and this could lead to gaps in the epithelial barrier. This protective layer of cells is critical to homeostasis. How does our body counter epithelial cell death and damage to maintain homeostasis?

Nucleus is the organelle that contains chromosomes

1. aspect is nothing really because the answer is right in front of your face

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.