How does water exhibit capillary action and what is its significance in plant biology?

• A. Water exhibits capillary action through diffusion, which is important for gas exchange in plant cells.
• B. Water exhibits capillary action through osmosis, which aids in the absorption of minerals from the soil.
• C. Water exhibits capillary action through evaporation, which helps in cooling the plant leaves.
• D. Water exhibits capillary action through cohesion and adhesion, allowing it to move upward against gravity, which is crucial for transporting nutrients in plants.

Answer: (D)

Verified step by step guidance

1. Understand the concept of capillary action: Capillary action is the ability of a liquid to flow in narrow spaces without the assistance of external forces, and sometimes in opposition to gravity. This phenomenon is primarily due to the cohesive and adhesive properties of the liquid.
2. Explore the role of cohesion and adhesion: Cohesion refers to the attraction between molecules of the same substance, while adhesion refers to the attraction between molecules of different substances. In the case of water, cohesive forces are due to hydrogen bonding between water molecules, and adhesive forces occur between water molecules and the walls of the plant's xylem vessels.
3. Analyze how capillary action works in plants: In plants, water moves upward through the xylem vessels from the roots to the leaves. This movement is facilitated by capillary action, where adhesion helps water molecules stick to the walls of the xylem, and cohesion helps pull additional water molecules along.
4. Consider the significance of capillary action in nutrient transport: Capillary action is crucial for transporting water and dissolved nutrients from the soil to various parts of the plant. This upward movement is essential for maintaining plant hydration and nutrient supply, which are vital for photosynthesis and growth.
5. Reflect on the overall importance of capillary action in plant biology: Without capillary action, plants would struggle to transport water and nutrients efficiently, which would affect their ability to perform photosynthesis, grow, and survive. This process is a key component of the plant's vascular system, ensuring the distribution of essential resources throughout the plant.