Which property allows water molecules to stick to other water molecules as they move up the xylem?

• A. Adhesion
• B. Capillary action
• C. Cohesion
• D. Surface tension

Answer: (C)

Verified step by step guidance

1. Understand the concept of cohesion: Cohesion refers to the attraction between molecules of the same substance. In the case of water, this is due to hydrogen bonding between water molecules.
2. Recognize the role of cohesion in plant biology: In plants, cohesion helps water molecules stick together as they move through the plant's vascular system, particularly the xylem.
3. Identify the process of water movement in plants: Water moves from the roots to the leaves through the xylem, a process driven by transpiration and facilitated by cohesive forces.
4. Differentiate between cohesion and adhesion: While cohesion involves water molecules sticking to each other, adhesion refers to water molecules sticking to other surfaces, such as the walls of the xylem.
5. Connect cohesion to the movement of water in the xylem: As water evaporates from the leaves, cohesive forces pull more water molecules up through the xylem, maintaining a continuous column of water.