Assistant Laboratory Animal Technician (ALAT) Practice Exam

Which of the following is true regarding vectors?

1. They are usually larger mammals.

2. They only transmit viruses.

3. They can transmit disease from one species to another.

4. They are always visible to the naked eye.

The correct answer is: They can transmit disease from one species to another.

Vectors are organisms that can carry and transmit pathogens from one host to another, often without getting affected themselves. This process is crucial in the spread of diseases, particularly in zoonotic diseases where transmission occurs between animals and humans. The statement that vectors can transmit disease from one species to another is accurate because many vectors, such as mosquitoes, ticks, and fleas, play significant roles in the epidemiology of various infectious diseases. For example, mosquitoes are well known for transmitting diseases like malaria and West Nile virus, which can affect both humans and other animal species. The other statements are inaccurate in the context of vectors. For instance, vectors are not exclusively larger mammals; they can also be insects, arachnids, and other small organisms. While many vectors transmit viruses, they also transmit bacteria, parasites, and other pathogens. Moreover, vectors are not always visible to the naked eye; many, such as certain types of bacteria or microscopic parasites, require a microscope for visibility. Thus, the definition and function of vectors align perfectly with the statement regarding their role in transmitting diseases across different species.