Water moves up a plant because of hydrogen bonds by a process called __________.

• A. cohesion-tension
• B. active transport
• C. facilitated diffusion
• D. diffusion

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the process of water movement in plants. Water moves through the xylem, which is a specialized tissue responsible for transporting water and nutrients from the roots to the leaves.
2. Step 2: Recognize the role of hydrogen bonds in water movement. Hydrogen bonds allow water molecules to stick together (cohesion) and also adhere to the walls of the xylem (adhesion). This is crucial for upward movement.
3. Step 3: Learn about the cohesion-tension mechanism. Cohesion refers to the attraction between water molecules, while tension is created by the evaporation of water from the leaves (transpiration). This process generates a negative pressure that pulls water upward.
4. Step 4: Compare the given options. Active transport involves energy and is used for moving substances against a concentration gradient, which is not relevant here. Facilitated diffusion and diffusion are passive processes but do not involve hydrogen bonds or the tension mechanism.
5. Step 5: Conclude that the correct process is cohesion-tension, as it specifically describes the role of hydrogen bonds and the tension created by transpiration in moving water up a plant.