Question

Which statement is true about obligate anaerobes?

A) They live exclusively by cellular respiration or by anaerobic respiration.
B) They will use O2 if it is present, but can obtain energy by fermentation if needed.
C) They are poisoned by O2.
D) They obtain energy by oxidizing ferrous ions.
E) They use O2 for cellular respiration and cannot grow without it.

Answer 1

Obligate anaerobes cannot grow in the presence of oxygen and obtain energy through fermentation or anaerobic respiration.

Step-by-step explanation:

Obligate anaerobes are organisms that cannot grow in the presence of oxygen and depend on fermentation or anaerobic respiration to obtain energy. They are poisoned by oxygen, as they lack the necessary enzymes to protect against oxidative stress.

Examples of obligate anaerobes include certain bacteria like Clostridia.