Part C: Bonus -- choose one to answer, 3 points

a. What is Treg cell? What’s its function, and result of its deficiency?

b. Why it’s challenging to develop HIV vaccines? Explain at least 3 reasons.

Part B: Brief Answer – Choose one to answer (10 points)

 a. If a pathogenic bacterium enters a skin wound, describe how the adaptive immune system responds to the viral infection. Identify and explain the roles of at least four components of the adaptive immune response, and describe how this process leads to the development of long-term protection.

b. If a pathogenic virus enters a skin wound, describe how the adaptive immune system responds to the viral infection. Identify and explain the roles of at least four components of the adaptive immune response, and describe how this process leads to the development of long-term protection.

Part B: Brief Answer – Gram-positive and Gram-negative bacteria each possess unique cell wall or plasma membrane features that cause them to respond differently to certain antimicrobial treatments. (9 points)

a. Name one antimicrobial drug that works specifically on each group but not the other, and explain the rationale for why it is effective for one group but resisted by the other.

b. Name one physical or chemical treatment that works specifically on each group but not the other, and explain the rationale for why it affects one group but not the other.

Therefore, you would need to provide four antimicrobial treatments in total.

·  One drug that works specifically on Gram-positive but not Gram-negative

·  One drug that works specifically on Gram-negative but not Gram-positive

·  One treatment effective specifically on Gram-positive but not Gram-negative

·  One treatment effective specifically on Gram-negative but not Gram-positive

Part B: Brief Answer – How is the replication of the viral genome of retroviruses unique among the viruses? Explain the following: the enzyme they use to replicate their genome, the flow of genetic information in retroviruses, where in the host cell this genome replication takes place, how the viral DNA becomes part of the host cell’s genetic material, and how long-term latent infection can develop. (8 points)

Which of the following is required for initial activation of CD4⁺ T cells?

Which statement best explains why fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridioides difficile infection?

Botulism results from ingestion of a heat-labile protein exotoxin produced by Clostridium botulinum. Which of the following BEST explains why proper home-canning procedures prevent botulism?

Part B: Brief Answer -- Choose one to answer (6 points)

a. A person has antibodies against the measles virus. List and describe three ways in which these antibodies could be acquired.

b. Define the three types of symbiosis, explain the relationship, and provide one microbiology-related example for each type.

Which of the following does not achieve sterilization?

Part B: Brief Answer – Describe the innate immune response to a small skin cut. Identify and explain the roles of at least four components involved , and summarize how they work together to prevent infection. (8 points)