Water uptake in roots via osmosis

Steps:

• Identify key mechanism: water moves from soil into roots by osmosis due to water potential gradient.
• Evaluate row 1: soil has higher water potential than root cells, driving passive flow.
• Evaluate row 2: osmosis is the diffusion of water across semi-permeable membranes.
• Confirm rows 3 and 4 likely involve errors like active transport or uphill gradients.

Why A is correct:

• Rows 1 and 2 align with osmosis definition: water moves down a water potential gradient from soil (higher ψ) to root cells (lower ψ) passively across membranes.

Why the others are wrong:

• B includes row 4, which misstates process as energy-requiring active transport.
• C pairs row 2 (correct) with row 3, which incorrectly claims movement against the gradient.
• D combines rows 3 and 4, both erroneous as uptake is passive, not active or against gradient.

Final answer: A