Energy from respiration powers active transport

Steps:

• Aerobic respiration generates ATP, the main energy source for cells.
• The chemical blocks aerobic respiration, reducing ATP production.
• Nitrate ions enter roots via active transport, which requires ATP to move against concentration gradients.
• With less ATP, active transport slows, decreasing nitrate absorption.

Why C is correct:

• Active transport uses ATP from respiration to pump ions like nitrate against gradients, per the definition of active transport in biology.

Why the others are wrong:

• A: Anaerobic respiration releases energy via ATP, though less efficiently than aerobic.
• B: Cells can switch to anaerobic respiration, so they still respire.
• D: Diffusion is passive and requires no energy, so respiration doesn't affect it.

Final answer: C