Which of the following statements is true about all forms of anaerobic respiration?

• A. They always produce ethanol as a byproduct.
• B. They require molecular oxygen to function.
• C. They produce more ATP per glucose molecule than aerobic respiration.
• D. They use an electron transport chain with a final electron acceptor other than oxygen.

Answer: (D)

Verified step by step guidance

1. Understand the concept of anaerobic respiration: Anaerobic respiration is a type of cellular respiration that occurs in the absence of oxygen. Unlike aerobic respiration, it uses a final electron acceptor other than oxygen in its electron transport chain.
2. Analyze the first statement: 'They always produce ethanol as a byproduct.' This is incorrect because ethanol production is specific to certain types of anaerobic respiration, such as alcoholic fermentation in yeast. Other organisms may produce different byproducts, such as lactic acid.
3. Evaluate the second statement: 'They require molecular oxygen to function.' This is incorrect because anaerobic respiration, by definition, occurs without oxygen. Oxygen is not involved in the process.
4. Examine the third statement: 'They produce more ATP per glucose molecule than aerobic respiration.' This is incorrect because anaerobic respiration is less efficient than aerobic respiration and produces fewer ATP molecules per glucose molecule.
5. Confirm the correct statement: 'They use an electron transport chain with a final electron acceptor other than oxygen.' This is true because anaerobic respiration relies on an electron transport chain, but the final electron acceptor is a substance other than oxygen, such as nitrate, sulfate, or carbon dioxide, depending on the organism.