What property of water allows it to move upward from the roots to the leaves in plants?

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

Answer: (A)

Verified step by step guidance

1. Begin by understanding the concept of capillary action, which is the ability of a liquid to flow in narrow spaces without the assistance of external forces like gravity. This is crucial for water movement in plants.
2. Next, explore the role of cohesion, which refers to the attraction between molecules of the same substance. In water, this is due to hydrogen bonding, which helps maintain a continuous column of water as it moves upward.
3. Consider adhesion, which is the attraction between molecules of different substances. In plants, water molecules adhere to the walls of the xylem vessels, aiding in upward movement.
4. Examine surface tension, which is the elastic tendency of a fluid surface that makes it acquire the least surface area possible. While important, it primarily affects water at the surface rather than in the xylem.
5. Integrate these concepts to understand how they collectively contribute to the movement of water from roots to leaves: capillary action is facilitated by cohesion and adhesion, allowing water to defy gravity and travel through the plant's vascular system.