Answer:
The answer is vertebrate.
Explanation:
Vertebrates are those animals that have a central spinal cord. Fish, Chicken and rabbit can be classified as vertebrates because they all have a spinal cord. The vertebrate is a big term that is further divided into different classes for example Fish, amphibians, mammals, avian, and reptiles,
Answer:
A laboratory mouse might not be an appropriate, susceptible host; an experiment with a laboratory rabbit may be needed.
Explanation:
Pathogens are disease causing organisms and in most of the cases, they are host specific,
In this case, the pathogen (microorganism X) was isolated from an infected rabbit's ear and cultured. Th most suitable host to test the pathogenicity of the microbe would have been a rabbit because that is where it was isolated initially.
<em>A mouse might not be a susceptible host, an experiment with a laboratory rabbit may be needed to affirm the pathogenicity of the isolated organism.</em>