What properties of water allow it to move against gravity in the xylem of plants?

• A. Density and buoyancy
• B. Polarity and solubility
• C. Surface tension and viscosity
• D. Cohesion and adhesion

Answer: (D)

Verified step by step guidance

1. Understand that water movement in plants, specifically in the xylem, is a process known as capillary action, which is crucial for transporting water from roots to leaves.
2. Recognize that cohesion refers to the attraction between water molecules due to hydrogen bonding. This property allows water molecules to stick together, forming a continuous column in the xylem.
3. Identify adhesion as the attraction between water molecules and the walls of the xylem vessels. This property helps water to climb up the walls of the xylem against gravity.
4. Combine the effects of cohesion and adhesion to understand capillary action: cohesion keeps the water column intact, while adhesion helps the water to adhere to the xylem walls, facilitating upward movement.
5. Consider the role of transpiration, which creates a negative pressure in the leaves, pulling water upward through the xylem, aided by the cohesive and adhesive properties of water.