AST Surgical Technologist Practice Exam

Which microbes live without oxygen?

1. Aerobes

2. Microaerophiles

3. Facultative anaerobes

4. Anaerobes

The correct answer is: Anaerobes

The correct answer is the group of microbes known as anaerobes. Anaerobes are organisms that thrive in environments devoid of oxygen. They utilize anaerobic metabolic processes, such as fermentation, to generate energy from organic compounds. This group can be further divided into obligate anaerobes, which cannot survive in the presence of oxygen, and facultative anaerobes, which can switch between aerobic and anaerobic metabolism depending on the environmental conditions. In contrast, aerobes are organisms that require oxygen for growth, microaerophiles need reduced levels of oxygen, and facultative anaerobes are capable of using oxygen but can also live without it. The defining characteristic of anaerobes is their ability to live and grow in the complete absence of oxygen, making them unique among these categories.