Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which of these animals would be classified as having a genetic mutation affecting their immune system?

1. Ragdoll cat

2. Beagle dog

3. Nude mouse

4. Arabian horse

The correct answer is: Nude mouse

The nude mouse is classified as having a genetic mutation affecting its immune system because it possesses a mutation in the gene responsible for the development of skin and immune cells. This mutation results in a lack of hair and a severely compromised immune system, making the nude mouse a popular model organism for immunological studies and cancer research. These mice are incapable of producing T cells—critical components of the immune response—making them an important subject for understanding immune deficiencies and testing therapies in environments where a normal immune response is not present. In contrast, the other animals listed do not inherently possess mutations that primarily affect their immune systems in the same way. Ragdoll cats, Beagle dogs, and Arabian horses may have various health issues, but they are not defined by a genetic mutation affecting their immune function like the nude mouse.