Question 1

Which of the following best explains why RNA-dependent RNA polymerase (RDRP) is an ideal target for antiviral drugs?

Accepted Answer

RDRP is not found in human cells, so targeting it minimizes harm to the patient.

Question 2

A patient is prescribed tetracycline for a bacterial infection. Which of the following side effects is most likely if the patient is a child, and what is the underlying mechanism?

Accepted Answer

Brown discoloration of teeth due to tetracycline binding to calcium in developing teeth.

Question 3

A sample of ocean water is diluted in a 1:10 series. 0.1 mL of the second dilution is plated, and 191 colonies are counted after incubation. What is the original concentration of bacteria in the sample in cfu/mL?

Accepted Answer

$$191,000$$

Question 4

Which of the following best describes the function of the viral envelope?

Accepted Answer

It mimics the host cell membrane, helping the virus evade the immune system.

Question 5

Which of the following antibiotics targets the 50s subunit of the bacterial ribosome and may cause arrhythmia as a side effect?

Accepted Answer

Azithromycin

Question 6

A patient develops severe anemia after being treated with penicillin. Which type of hypersensitivity reaction is most likely responsible, and what is the mechanism?

Accepted Answer

Type II; IgG antibodies bind to penicillin-coated red blood cells, activating complement and causing cell lysis.

Question 7

Which of the following statements about the adaptive immune system is correct?

Accepted Answer

It relies on memory cells to mount a faster and stronger response upon second exposure to an antigen.

Question 8

Which of the following best explains why antibiotics that inhibit bacterial ribosomes can also cause side effects in human cells?

Accepted Answer

Mitochondria in human cells have ribosomes similar to bacterial ribosomes, so these antibiotics can disrupt mitochondrial function.

Question 9

Which of the following is the correct sequence of events in the lytic viral replication cycle?

Accepted Answer

Attachment, uncoating, assembly, lysis

Question 10

A patient with a history of multiple antibiotic allergies is prescribed a sulfa drug. Which severe side effect should the clinician be most concerned about?

Accepted Answer

Stevens-Johnson Syndrome

Question 11

Which of the following best describes the role of Helper T cells (CD4 cells) in the immune response?

Accepted Answer

They activate both B cells and cytotoxic T cells by recognizing antigens presented on MHC II.

Question 12

Which of the following is true regarding the difference between Gram-positive and Gram-negative bacteria in relation to beta-lactam antibiotics?

Accepted Answer

Beta-lactams are effective only against Gram-positive bacteria because they target peptidoglycan, which is more abundant in Gram-positive cell walls.

Question 13

A patient is exposed to poison ivy and develops a rash 48 hours later. Which type of hypersensitivity reaction is this, and what is the primary immune mechanism involved?

Accepted Answer

Type IV; T cell-mediated cytotoxicity and macrophage activation

Question 14

Which of the following best explains why red blood cell infections are particularly dangerous?

Accepted Answer

Red blood cells lack MHC I, so they cannot present antigens to cytotoxic T cells.

Question 15

Which antibody is primarily responsible for agglutination and complement activation, and what is its structure?

Accepted Answer

IgM; pentamer

Question 16

A patient receives an antivenom and subsequently develops nephritis due to immune complex deposition in the kidneys. Which type of hypersensitivity reaction is this, and what is the underlying process?

Accepted Answer

Type III; immune complexes accumulate in capillaries, activating complement and causing inflammation

Question 17

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies bind to pathogens, making them easier for phagocytes to recognize and engulf.

Question 18

Which of the following is a correct statement about the Major Histocompatibility Complex (MHC)?

Accepted Answer

Red blood cells lack MHC I because they lose their nucleus during maturation.

Question 19

A patient is infected with a single-stranded negative-sense RNA virus. Which enzyme must be present in the viral capsid for successful replication, and why?

Accepted Answer

RNA-dependent RNA polymerase; to synthesize complementary positive-sense RNA for translation

Comprehensive Study Notes: Viruses, Antimicrobial Drugs, Immunology, and Hypersensitivity

Study Guide - Practice Questions

Study Guide - Flashcards