9.1 Transport in the Xylem of Plants

Which of the following statements best describes the role of transpiration in water transport in plants?

A. Transpiration only occurs in the roots to absorb water from the soil.

B. Transpiration is the process by which water is transported from the leaves to the roots.

C. Transpiration involves the evaporation of water from plant leaves, creating a pull that aids in water transport.

D. Transpiration prevents the uptake of mineral ions at the root hair cells.

How does the cohesion-tension theory explain water transport against gravity in plants?

A. Water molecules sticking together create tension, which pushes water upwards.

B. Cohesion between water molecules and tension created by transpiration enable water transport.

C. Cohesion causes water molecules to separate, reducing tension and allowing water transport.

D. Tension between water molecules breaks their cohesion, facilitating water movement.

What is the primary role of xylem vessels in the transport of water in plants?

A. Absorbing water from the soil.

B. Facilitating gas exchange for photosynthesis.

C. Conducting water and minerals from roots to leaves.

D. Storing water for later use.

Which of the following factors primarily contributes to the movement of water into the roots of plants?

A. Transpiration pull from the leaves.

B. Active uptake of mineral ions at the root hair cells.

C. Evaporation of water from the soil.

D. Adhesion of water molecules to xylem vessels.

How does the adhesive property of water contribute to its transport in plants?

A. It causes water molecules to stick to each other, creating a continuous water column.

B. It allows water molecules to stick to the walls of the xylem vessels, aiding in upward movement.

C. It prevents water molecules from sticking to the walls of the xylem vessels.

D. It reduces the tension forces generated by evaporation in leaf cells.

a) Explain the process of transpiration and how it contributes to water transport in plants. [4]

b) Discuss how the transpiration pull facilitates the movement of water from the roots to the leaves in plants. [3]

a) Elaborate on the cohesion-tension theory and how it enables water transport against gravity in plants. [4]

b) How does the adhesive property of water contribute to the tension forces that aid in water transport? [3]

a) Discuss how the active uptake of mineral ions at the root hair cells influences water transport in plants. [3]

b) Explain how the increased solute concentration in root cells leads to water entering the roots by osmosis. [4]

a) Define transpiration and explain its role in gas exchange necessary for photosynthesis. [3]

b) How does the cohesion of water molecules contribute to the transpiration pull? [3]

c) Discuss the impact of environmental factors on the rate of transpiration in plants. [4]

a) Outline the pathway of water transport from roots to leaves in plants. [4]

b) Explain the role of xylem vessels in water transport. [3]

c) How does the process of evaporation in leaf cells generate tension forces aiding in water transport? [3]