Which term describes organisms that do not require oxygen?

Which term describes organisms that do not require oxygen?

• A. Anaerobic
• B. Aerobic
• C. Prokaryote
• D. Eukaryote

Answer: (A)

Organisms that do not require oxygen are described as anaerobic. This term captures the way these organisms obtain energy and grow without needing oxygen, and in many cases they grow best or exclusively in oxygen-free environments. Some anaerobes cannot tolerate oxygen at all (obligate anaerobes), while others can switch to using oxygen if it’s available (facultative anaerobes), but the defining feature is their ability to live without oxygen. In contrast, aerobic describes organisms that require oxygen, and prokaryote and eukaryote refer to cellular organization rather than oxygen needs, so they don’t directly answer the question.

Organisms that do not require oxygen are described as anaerobic. This term captures the way these organisms obtain energy and grow without needing oxygen, and in many cases they grow best or exclusively in oxygen-free environments. Some anaerobes cannot tolerate oxygen at all (obligate anaerobes), while others can switch to using oxygen if it’s available (facultative anaerobes), but the defining feature is their ability to live without oxygen. In contrast, aerobic describes organisms that require oxygen, and prokaryote and eukaryote refer to cellular organization rather than oxygen needs, so they don’t directly answer the question.