Certified Crop Advisor Practice Exam

Which type of pathogen typically survives only in living tissue?

1. Bacteria

2. Virus

3. Fungi

4. Protozoa

The correct answer is: Virus

Viruses are unique among pathogens as they cannot replicate or survive outside of living host cells. They are obligate parasites, meaning they must invade a living organism to propagate. Once inside a host cell, viruses hijack the cellular machinery to replicate their genetic material and produce more virus particles, which can then infect further host cells. This requirement for living tissue is what differentiates viruses from other pathogens, such as bacteria and fungi, which can often survive in a variety of environments, including inanimate surfaces.