Organisms that require oxygen for metabolism are referred to as…

• A. Facultative aerobes.
• B. Obligate aerobes.
• C. Facultative anaerobes.
• D. Microaerophiles.

Answer: (B)

Verified step by step guidance

1. Understand the terminology: 'Obligate aerobes' are organisms that require oxygen for their metabolism and cannot survive without it.
2. Differentiate between the terms: 'Facultative aerobes' can use oxygen but can also survive without it, unlike obligate aerobes.
3. Consider 'Facultative anaerobes': These organisms can grow with or without oxygen, using fermentation or anaerobic respiration when oxygen is absent.
4. Examine 'Microaerophiles': These organisms require oxygen but at lower concentrations than are present in the atmosphere.
5. Identify the correct term: Since the question specifies organisms that require oxygen for metabolism, the correct term is 'Obligate aerobes'.