Question 1

Which of the following best describes the primary function of interferons during a viral infection?

Accepted Answer

They signal neighboring cells to enter an antiviral state and inhibit viral replication.

Question 2

A patient with a genetic defect in their major histocompatibility complex (MHC) molecules would most likely have difficulty with which aspect of viral immunity?

Accepted Answer

Activating cytotoxic T cells to recognize and kill infected cells.

Question 3

Which of the following is a key difference between innate and adaptive immunity in the context of viral infections?

Accepted Answer

Innate immunity provides a rapid, non-specific response, while adaptive immunity develops more slowly and is highly specific.

Question 4

Which process is illustrated by the following sequence: Antibodies bind to viral particles, marking them for ingestion and destruction by phagocytic cells?

Accepted Answer

Opsonization

Question 5

A virus infects a cell, which then releases interferons. These interferons bind to receptors on neighboring cells, leading to the upregulation of interferon-stimulated genes (ISGs). Which of the following is a likely outcome of ISG activation?

Accepted Answer

Degradation of viral RNA and inhibition of viral protein synthesis.

Question 6

Which of the following best explains why excessive activity of natural killer (NK) cells during chronic viral infection can be harmful?

Accepted Answer

Excessive NK cell activity can cause tissue damage and immunopathology.

Question 7

During a viral infection, which immune cell type is primarily responsible for recognizing and killing infected cells that display viral antigens on MHC class I molecules?

Accepted Answer

Cytotoxic T cells (CD8+)

Question 8

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

Accepted Answer

They coordinate the immune response by activating B cells and cytotoxic T cells through cytokine secretion.

Question 9

A patient is exposed to a virus for the second time. Which of the following best explains why their immune response is faster and more robust compared to the first exposure?

Accepted Answer

Memory B and T cells generated during the first infection respond rapidly upon re-exposure.

Question 10

Which of the following scenarios best illustrates the concept of host tolerance rather than resistance?

Accepted Answer

A host minimizes tissue damage and inflammation despite persistent viral presence.

Question 11

Which of the following is the most likely consequence if the skin barrier is disrupted, as shown in the first image?

Accepted Answer

Increased susceptibility to viral, bacterial, and toxin entry into the body.

Question 12

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

Accepted Answer

Antibodies coat infected cells, allowing NK cells to recognize and kill them via Fc receptors.

Question 13

Which of the following equations best represents the relationship between the rate of viral clearance ($$C$$), the number of cytotoxic T cells ($$T$$), and the efficiency of apoptosis induction ($$E$$)?

Accepted Answer

$$C = T 	imes E$$

Question 14

A new viral strain is able to inhibit the production of interferons in infected cells. Which of the following is the most likely consequence?

Accepted Answer

The virus will replicate more efficiently due to reduced antiviral signaling.

Question 15

Which of the following best explains why the humoral response (antibody production) is considered part of the adaptive immune system?

Accepted Answer

It is highly specific to the infecting virus and involves immunological memory.

Question 16

Which of the following best describes the process by which cytotoxic T cells induce apoptosis in virus-infected cells?

Accepted Answer

They release perforin to create pores and granzymes to trigger apoptosis.

Question 17

Which of the following factors is LEAST likely to influence an individual's resistance to viral infection?

Accepted Answer

The color of the individual's hair

Question 18

A virus has evolved to rapidly change its surface proteins, making it difficult for antibodies to recognize it. This is an example of:

Accepted Answer

Viral immune evasion

Question 19

Which of the following best describes the time course of immune responses to a primary viral infection, as shown in the provided graph?

Accepted Answer

Interferon and NK cell activity peak early, followed by a later rise in antibody levels.

Host Resistance to Viral Infections: Mechanisms and Immune Responses

Study Guide - Practice Questions

Study Guide - Flashcards