Describe how water moves from roots to the leaves.

Water movement from roots to leaves is a process known as transpiration and it occurs in several steps:

1. Absorption: The process begins in the roots where water is absorbed from the surrounding soil through root hairs. This is facilitated by osmosis, a process where water moves from an area of high concentration (the soil) to an area of low concentration (the root cells).

2. Root Pressure: As more and more water is absorbed, it creates a pressure known as root pressure that helps in pushing the water upwards into the stem.

3. Capillary Action: Water then moves up the stem through a process known as capillary action. This is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to, external forces like gravity.

4. Transpiration Pull: As water evaporates from the leaves, it creates a suction force known as the transpiration pull. This is the main driver that pulls water up from the roots to the leaves.

5. Cohesion and Adhesion: Water molecules are attracted to each other (cohesion) and to the walls of the xylem vessels (adhesion). This helps them stick together and to the sides of the vessels, assisting in their upward movement.

6. Evaporation: Finally, the water reaches the leaves where it evaporates from the leaf surface in a process called transpiration. This loss of water from the leaves pulls more water up from the roots, continuing the cycle.