Anaerobic respiration in humans produces less energy than aerobic

Steps:

• Define aerobic respiration: glucose fully oxidized to CO2 and H2O, yielding ~36-38 ATP per glucose.
• Define anaerobic respiration in humans: glucose fermented to lactate, yielding only 2 ATP per glucose.
• Compare: anaerobic releases far less energy due to incomplete glucose breakdown.
• Test options: A incorrect (occurs when O2 demand > supply); B incorrect (no CO2 produced); C partially accurate but incomplete phrasing; D directly states the energy deficit.

Why D is correct:

• Anaerobic yields 2 ATP versus 36-38 ATP in aerobic, per the net energy equation from glycolysis alone without full oxidation.

Why the others are wrong:

• A: Anaerobic occurs during oxygen shortage, not excess.
• B: Lactic acid fermentation produces lactate, not CO2.
• C: Vague phrasing omits "energy," making it imprecise.

Final answer: D