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 only found in viruses and not 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 to occur if the patient is a young child, and what is the underlying mechanism?

Accepted Answer

Brown discoloration of teeth because tetracycline binds to calcium in developing teeth.

Question 3

During a plate count assay, you dilute a 1 mL sample of water in a 1:10 dilution series. You plate 0.1 mL from the second dilution tube and count 191 colonies after incubation. What is the original concentration of bacteria in the sample?

Accepted Answer

$$191,000\ \mathrm{cfu}/\mathrm{mL}$$

Question 4

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

Accepted Answer

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

Question 5

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 hypersensitivity; IgG antibodies bind to penicillin-coated red blood cells, activating complement and leading to cell lysis.

Question 6

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

Accepted Answer

It has memory, allowing for a faster and stronger response upon second exposure to the same antigen.

Question 7

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 8

A virus with a single-stranded negative-sense RNA genome must bring which enzyme with it in the capsid to initiate replication in the host cell?

Accepted Answer

RNA-dependent RNA polymerase (RDRP)

Question 9

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

Accepted Answer

Mitochondria have ribosomes similar to those of bacteria, so ribosomal inhibitors can disrupt mitochondrial function.

Question 10

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

Accepted Answer

IgM; pentamer

Question 11

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 12

Which of the following is a common side effect of gentamycin, and what is the underlying reason?

Accepted Answer

Hearing loss due to mitochondrial toxicity in the ear

Question 13

Which of the following best describes the process of opsonization?

Accepted Answer

Antibodies bind to pathogens, enhancing their recognition and phagocytosis by macrophages.

Question 14

Which of the following is true regarding the Major Histocompatibility Complex (MHC) in human cells?

Accepted Answer

Macrophages and dendritic cells express MHC II.

Question 15

A newborn develops severe anemia during the second pregnancy of an Rh-negative mother with an Rh-positive baby. What is the immunological basis for this condition?

Accepted Answer

Maternal IgG antibodies cross the placenta and destroy fetal red blood cells.

Question 16

Which of the following best explains why sulfa drugs (such as trimethoprim) do not harm human cells?

Accepted Answer

Human cells do not synthesize folate and instead obtain it from the diet.

Question 17

Which of the following is a function of the spleen in the immune system?

Accepted Answer

Filtering out immune complexes from the blood

Question 18

Which of the following best describes the role of helper T cells in the immune response?

Accepted Answer

They coordinate the adaptive immune response by activating B cells and cytotoxic T cells.

Question 19

Which of the following is a correct statement about the lytic and lysogenic cycles of viral replication?

Accepted Answer

The lysogenic cycle allows the virus to hide from the immune system by integrating into the host chromosome.

Question 20

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

Accepted Answer

Red blood cells lack MHC I and cannot present antigens to the immune system.

Comprehensive Study Notes: Viruses, Antimicrobial Drugs, and Immunology

Study Guide - Practice Questions

Study Guide - Flashcards