Facultative anaerobe is a term frequently used in microbiology to describe organisms that can survive with or without the presence of oxygen. Some synonyms for facultative anaerobe include versatile anaerobe, adaptable anaerobe, and facultative aerobe. These terms all refer to microorganisms that can switch between aerobic and anaerobic respiration depending on the availability of oxygen. Other related terms include obligate anaerobe, which cannot survive in the presence of oxygen, and obligate aerobe, which requires oxygen for survival. Understanding these terms is important for studying and categorizing various microorganisms based on their physiological characteristics and environmental requirements.