answer key

Section A: Host-Microbe Interactions

Multiple Choice:

1. b) Commensal

2. c) Hygiene hypothesis

3. d) Induction of allergies

Essay:

4. Answers may vary but should cover the role of normal microbiota in protection against pathogens, contribution to the development of the immune system, and discussion on the hygiene hypothesis.

5. Answers may vary but should include definitions and examples of mutualistic, commensal, and parasitic symbiotic relationships among microbes, and their impacts on human health and disease.

6. Answers may vary but should define primary pathogens, opportunistic pathogens, and virulence factors, and discuss how these factors contribute to infectious diseases.

Section B: Viruses, Viroids, and Prions

Matching:

1. D - Prions

2. A - Lytic cycle

3. B - Lysogenic cycle

4. C - Transduction

Essay:

7. Answers may vary but should describe viral particle shapes, steps in the animal virus replication cycle, and compare entry and exit steps between animal viruses and bacteriophages.

8. Answers may vary but should discuss viral latency, examples of viruses that establish latency, and how they can reactivate to cause disease.

9. Answers may vary but should define viroids and prions and compare them to viruses in terms of structure, replication, and disease-causing mechanisms.

Section C: Epidemiology

Multiple Choice:

10. b) Epidemiology

11. a) Incidence

Matching:

1. A - Endemic

2. B - Epidemic

3. C - Pandemic

4. D - Outbreak

Essay:

12. Answers may vary but should cover the steps in the chain of infection, types of reservoirs, modes of transmission, and factors influencing disease outcomes.

13. Answers may vary but should discuss the role of public health organizations in preventing and controlling infectious diseases and key components of effective disease surveillance and response systems.

14. Answers may vary but should discuss factors influencing the emergence and reemergence of infectious diseases, provide examples of recent outbreaks, and analyze contributing factors.

This answer key provides guidance on the expected responses for each question and essay prompt.