How does capillarity, a property of water involving cohesion and adhesion, help sustain life in plants?

• A. It prevents water from evaporating from plant leaves.
• B. It enables plants to absorb nutrients directly from the soil.
• C. It causes water to repel from plant surfaces, reducing water loss.
• D. It allows water to move upward against gravity through plant vessels.

Answer: (D)

Verified step by step guidance

1. Understand the concept of capillarity: Capillarity is the ability of a liquid to flow in narrow spaces without the assistance of external forces like gravity. This property is crucial for the movement of water in plants.
2. Explore cohesion and adhesion: Cohesion refers to the attraction between molecules of the same substance, while adhesion is the attraction between molecules of different substances. In water, cohesion helps water molecules stick together, and adhesion helps them stick to the walls of plant vessels.
3. Examine how capillarity works in plants: In plants, capillarity allows water to move upward through the xylem vessels. The adhesive forces between water molecules and the walls of the vessels, combined with cohesive forces among water molecules, enable this upward movement against gravity.
4. Consider the role of capillarity in sustaining plant life: Capillarity is essential for transporting water from the roots to the leaves, where it is used in photosynthesis and other vital processes. This movement also helps distribute nutrients dissolved in water throughout the plant.
5. Reflect on the importance of capillarity: Without capillarity, plants would struggle to move water and nutrients from the soil to their leaves, impacting their growth and survival. This property is fundamental to the efficient functioning of vascular plants.