Anaerobic respiration requires no oxygen

Steps:

• Recall that respiration is the process cells use to release energy from glucose.
• Aerobic respiration uses oxygen to fully break down glucose, producing more energy.
• Anaerobic respiration happens without oxygen, leading to incomplete breakdown and byproducts like lactic acid.
• Identify the substance lacking in anaerobic conditions: oxygen.

Why D is correct:

• Anaerobic respiration is defined as cellular respiration without oxygen, as oxygen acts as the final electron acceptor in the electron transport chain.

Why the others are wrong:

• A. Carbon dioxide is a byproduct of both aerobic and anaerobic respiration, not a requirement.
• B. Glucose is the fuel substrate needed for both types of respiration.
• C. Lactic acid is a waste product of anaerobic respiration in animals, not a lacking substance.

Final answer: D