Question

______ bacterial cells do not use oxygen in their metabolism.
○ aerobic
○ anaerobic
○ facultative

Explanation:

To solve this, we analyze each option:

• Aerobic bacteria require oxygen for metabolism, so this is incorrect.
• Anaerobic bacteria do not use oxygen in their metabolic processes, which matches the description.
• Facultative bacteria can use oxygen but can also survive without it, so this is not the best fit as the question states "do not use oxygen" (implying a strict non - use, while facultative can use it sometimes).

Answer:

B. anaerobic