Assistant Laboratory Animal Technician (ALAT) Practice Exam

What is a key characteristic of gnotobiotic animals?

1. They are completely free of all microorganisms.

2. They have a known and controlled bacterial flora.

3. They are guaranteed to be pathogen-free.

4. They can be maintained in conventional housing.

The correct answer is: They have a known and controlled bacterial flora.

Gnotobiotic animals are defined by their known and controlled bacterial flora, making it possible to study the specific effects of these microorganisms on the host. This controlled environment allows researchers to understand how certain bacteria can influence physiological processes, immune responses, and overall health in a way that is not feasible in conventional animal models. The key characteristic of having a known and controlled bacterial flora distinguishes gnotobiotic animals from others that may have unpredictable microorganisms present. While gnotobiotic animals may still carry other types of microorganisms, the focus on their specific bacterial composition allows for precise and targeted research. Other characteristics related to gnotobiotic conditions, such as being pathogen-free or completely devoid of all microorganisms, could be misleading. Gnotobiotic animals may not necessarily be completely free of all microorganisms, as they can still have specific, intentionally introduced microorganisms. Additionally, while they may be free of specific pathogens, that does not guarantee they will be entirely free from all other types of microorganisms. Lastly, gnotobiotic animals are typically housed in specialized environments rather than conventional systems, which further emphasizes the importance of their unique conditions.