Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which term refers to animals that are nearly devoid of microorganisms but have been provided with known bacteria?

1. Germfree

2. Conventional

3. Gnotobiotic

4. Specific Pathogen-Free

The correct answer is: Gnotobiotic

The term that refers to animals that are nearly devoid of microorganisms but have been provided with known bacteria is gnotobiotic. Gnotobiotic animals are essential in research as they allow scientists to study the interactions between specific microorganisms and the host without the confounding effects of unknown microbes. This controlled environment is crucial for experiments aiming to understand the roles of specific bacteria in health and disease, as well as their impact on the immune system and metabolism. In contrast, germfree animals have no microorganisms at all, including both harmful and beneficial bacteria. Conventional animals carry a full spectrum of microorganisms found in a typical environment, and Specific Pathogen-Free animals are defined by the absence of certain known pathogens, but they may still harbor other microorganisms. Thus, the unique characteristic of gnotobiotic animals is the defined, limited presence of specific microorganisms, making it a key concept in biomedical research and studies involving microbiota.