Question 1

Which of the following best describes the mechanism of action for β-lactam antibiotics such as penicillin?

Accepted Answer

They inhibit the synthesis of peptidoglycan in bacterial cell walls, leading to cell lysis.

Question 2

A patient develops hives within minutes of exposure to peanuts. Which type of hypersensitivity reaction is this, and what is the primary antibody involved?

Accepted Answer

Type I hypersensitivity; IgE antibody

Question 3

Which of the following is a key feature of superantigens in the immune response?

Accepted Answer

They activate a large number of T cells by binding outside the normal antigen-binding site of MHC and TCR.

Question 4

Which of the following best explains why conjugate vaccines are more effective in infants than polysaccharide-only vaccines?

Accepted Answer

Conjugate vaccines link a weak antigen to a strong protein carrier, enabling T-cell dependent immunity.

Question 5

A patient with severe combined immune deficiency (SCID) is most likely to experience which of the following?

Accepted Answer

Frequent bacterial and viral infections due to lack of both B and T cells.

Question 6

Which of the following is a mechanism by which bacteria can develop resistance to antibiotics?

Accepted Answer

Producing enzymes that inactivate the antibiotic, such as β-lactamases.

Question 7

Which of the following drugs is most likely to cause permanent staining of teeth if administered to children?

Accepted Answer

Tetracycline

Question 8

Which of the following statements about nucleic acid vaccines is correct?

Accepted Answer

They introduce DNA or mRNA into host cells, which then produce pathogen antigens to stimulate immunity.

Question 9

A patient is treated with a drug that inhibits 1,3 β-D glucan synthase. Which type of infection is this drug most likely targeting?

Accepted Answer

Fungal infection (e.g., Candida)

Question 10

Which of the following best describes the function of checkpoint inhibitors in cancer immunotherapy?

Accepted Answer

They block inhibitory signals on T cells, enhancing their ability to attack tumor cells.

Question 11

Which of the following is a reason why antifungal drugs often have higher toxicity in humans compared to antibacterial drugs?

Accepted Answer

Fungi are eukaryotic and share many cellular features with human cells.

Question 12

Which of the following best explains why combination drug therapy is effective in treating HIV infections?

Accepted Answer

The probability of the virus developing resistance to multiple drugs simultaneously is much lower than to a single drug.

Question 13

Which of the following is a characteristic of Type IV hypersensitivity reactions?

Accepted Answer

They are mediated by T cells and result in tissue damage several hours after antigen exposure.

Question 14

Which of the following is the primary target of quinolone antibiotics?

Accepted Answer

DNA gyrase, inhibiting DNA supercoiling and replication

Question 15

A patient with HIV is prescribed a nucleoside reverse transcriptase inhibitor (NRTI). What is the mechanism of action of this drug?

Accepted Answer

It blocks reverse transcriptase, preventing the synthesis of viral DNA from RNA.

Question 16

Which of the following best describes the role of the gut microbiome in cancer immunotherapy?

Accepted Answer

Certain gut microbes can enhance the efficacy of immunotherapeutic treatments by modulating the immune response.

Question 17

Which of the following is a real-world example of an autoimmune disease caused by autoantibodies?

Accepted Answer

Type 1 diabetes mellitus

Question 18

Which of the following is a property of broad-spectrum antibiotics?

Accepted Answer

They are effective against both gram-positive and gram-negative bacteria.

Question 19

Which of the following is a likely consequence of overusing antibiotics in a population?

Accepted Answer

An increase in the number of antibiotic-resistant bacteria.

Question 20

Which of the following best describes the function of interferons in antiviral defense?

Accepted Answer

They stimulate antiviral protein production in uninfected cells, limiting viral spread.

Immune Disorders and Antimicrobial Therapy: Study Notes for Microbiology Students

Study Guide - Practice Questions

Study Guide - Flashcards