An axenic environment is one that __________ .
a. Exists in the human mouth
b. Contains only one species
c. Exists in the human colon
d. Both a and c

Verified step by step guidance

1. Understand the term 'axenic' in microbiology: it refers to an environment that is free from any other living organisms except for a single species or is completely sterile.
2. Analyze each option in the context of the definition: option (a) 'exists in the human mouth' is incorrect because the human mouth contains a diverse microbiota, not a single species or sterile environment.
3. Option (b) 'contains only one species' aligns with the definition of an axenic environment, which is typically a culture or environment with only one species present.
4. Option (c) 'exists in the human colon' is incorrect because the human colon hosts a complex and diverse microbial community, not an axenic environment.
5. Option (d) 'both a and c' is incorrect since neither the human mouth nor the colon represents an axenic environment.

Key Concepts

Axenic Environment

An axenic environment is a controlled setting that contains only a single species of microorganism, free from contamination by other species. It is often used in laboratory studies to observe pure cultures without interference from other microbes.

Microbial Diversity in the Human Body

The human body hosts diverse microbial communities, such as in the mouth and colon, where multiple species coexist. These environments are not axenic because they contain complex microbiota essential for health and digestion.

Pure Culture Techniques

Pure culture techniques involve isolating a single microbial species to study its characteristics without contamination. This is fundamental in microbiology to understand specific microbial behavior, which contrasts with natural mixed-species environments.