Active transport requires ATP energy in plants

Steps:

• Identify processes needing energy: active transport moves substances against concentration gradients using ATP.
• Evaluate options: gases like CO2 and O2 move by passive diffusion down gradients.
• Check ion uptake: nitrates enter roots via active transport proteins.
• Confirm water movement: xylem transport relies on passive transpiration pull.

Why C is correct:

• Nitrate uptake by root hair cells is active transport, using ATP to move ions against their concentration gradient (as per cell membrane transport laws).

Why the others are wrong:

• A: CO2 absorption occurs via passive diffusion through cell membranes.
• B: Oxygen absorption is passive diffusion into mesophyll cells.
• D: Water transport in xylem uses passive cohesion-tension from evaporation.

Final answer: C