Question 1

Which of the following best describes the difference between host resistance and host tolerance to viral infections?

Accepted Answer

Host resistance refers to the ability to reduce viral burden, while host tolerance refers to minimizing tissue damage without necessarily reducing viral load.

Question 2

Which of the following is NOT a function of interferons during a viral infection?

Accepted Answer

They directly destroy viral particles in the bloodstream.

Question 3

A patient with a genetic defect in their MHC class I molecules would most likely have impaired function in which immune cell type?

Accepted Answer

Cytotoxic T cells (CD8+)

Question 4

Which of the following best explains why the skin is considered a nonspecific barrier to viral infection?

Accepted Answer

It prevents the entry of a wide range of pathogens, regardless of their specific type.

Question 5

Natural Killer (NK) cells can destroy virus-infected cells by releasing which of the following molecules?

Accepted Answer

Perforin and granzymes

Question 6

Which process describes the coating of viral particles with antibodies to enhance their uptake and destruction by phagocytes?

Accepted Answer

Opsonization

Question 7

A viral infection triggers the production of interferons, which then induce the expression of ISGs in neighboring cells. What is the primary outcome of this process?

Accepted Answer

Establishment of an antiviral state that inhibits viral replication.

Question 8

Which of the following best describes the role of dendritic cells in the immune response to viral infection?

Accepted Answer

They act as antigen-presenting cells that activate T cells by presenting viral peptides on MHC molecules.

Question 9

Which of the following is a key feature of adaptive immunity that distinguishes it from innate immunity?

Accepted Answer

Immunological memory

Question 10

A patient is re-exposed to a virus they encountered years ago. Which immune cells are primarily responsible for the rapid and robust response that prevents reinfection?

Accepted Answer

Memory B and T cells

Question 11

Which of the following best explains why excessive NK cell activity during chronic viral infection can be harmful?

Accepted Answer

It can lead to tissue damage and immunopathology.

Question 12

Which of the following is the most crucial mechanism by which antibodies halt the viral life cycle?

Accepted Answer

Neutralization of viral particles

Question 13

Which of the following best describes the role of helper T cells (CD4+) in the immune response to viral infection?

Accepted Answer

They coordinate and enhance the functions of other immune cells through cytokine secretion.

Question 14

Which of the following factors does NOT significantly influence an individual's resistance to viral infection?

Accepted Answer

Blood type

Question 15

Which of the following best describes antibody-dependent cell-mediated cytotoxicity (ADCC)?

Accepted Answer

NK cells recognize and kill infected cells coated with antibodies.

Question 16

Which of the following is a direct result of cytotoxic T cell (CD8+) activity during a viral infection?

Accepted Answer

Induction of apoptosis in infected cells

Question 17

Which of the following best explains why viruses and hosts are engaged in an evolutionary arms race?

Accepted Answer

Viruses evolve to evade host defenses, while hosts evolve new mechanisms of resistance.

Question 18

Which of the following is a key difference between the humoral and cell-mediated branches of adaptive immunity?

Accepted Answer

Humoral immunity targets extracellular viruses with antibodies, while cell-mediated immunity targets intracellular viruses with cytotoxic T cells.

Question 19

Which of the following equations best represents the relationship between viral load ($$V$$), rate of viral replication ($$r$$), and rate of immune clearance ($$c) in a $$simplified model?

Accepted Answer

$$\frac{dV}{dt} = rV - cV$$

Question 20

A patient with a deficiency in helper T cells (CD4+) would most likely experience which of the following?

Accepted Answer

Impaired coordination of both humoral and cell-mediated immune responses

Host Resistance to Viral Infections: Mechanisms and Immune Responses

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