Question 1

Which of the following best describes the requirement for T cell activation?

Accepted Answer

T cells require two signals: specific antigen binding and differentiation of pathogen from non-pathogen.

Question 2

Which statement correctly distinguishes between active and passive immunity?

Accepted Answer

Active immunity involves the production of antibodies by the host after exposure to an antigen, while passive immunity involves receiving pre-formed antibodies.

Question 3

A patient receives a vaccine containing a protein conjugate. Which type of vaccine is this?

Accepted Answer

Protein conjugate vaccine

Question 4

Which of the following is a function of effector T$_{H}$ cells?

Accepted Answer

They activate macrophages and stimulate B cell antibody production.

Question 5

What is the role of IL-2 in T cell proliferation?

Accepted Answer

IL-2 acts as a growth factor, promoting auto-stimulation and proliferation of T cells.

Question 6

Which process describes the two-signal requirement for T cell activation?

Accepted Answer

Antigen binding to the T cell receptor and co-stimulation by a second signal from an antigen-presenting cell.

Question 7

Which equation best represents herd immunity threshold ($H$) in a population, given the basic reproduction number $R_0$?

Accepted Answer

$H = 1 - \frac{1}{R_0}$

Question 8

A patient is diagnosed with myasthenia gravis. Which mechanism is responsible for this autoimmune disease?

Accepted Answer

Antibodies block acetylcholine receptors at the neuromuscular junction.

Question 9

Which of the following is true about the difference between a monoclonal antibody and a polyclonal antiserum?

Accepted Answer

Monoclonal antibodies are derived from a single B cell clone and recognize one epitope, while polyclonal antiserum contains antibodies from multiple B cell clones recognizing multiple epitopes.

Question 10

Which of the following best describes the mechanism of Type I hypersensitivity (HS) reaction?

Accepted Answer

It involves IgE antibodies binding to mast cells, leading to degranulation and release of histamine.

Question 11

Which laboratory technique uses antibodies to detect a specific protein on an electrophoretic gel?

Accepted Answer

Western Blot

Question 12

Which of the following is a key difference between direct and indirect ELISA tests?

Accepted Answer

Direct ELISA detects antigen using a labeled primary antibody, while indirect ELISA detects antibody using a labeled secondary antibody.

Question 13

A newborn receives antibodies from its mother through breast milk. This is an example of:

Accepted Answer

Passive immunity

Question 14

Which of the following is a feature of activated macrophages?

Accepted Answer

They have increased phagocytic activity and secrete cytokines.

Question 15

Which statement about DNA/RNA-based vaccines is correct?

Accepted Answer

They provide immunity by introducing genetic material encoding antigenic proteins.

Question 16

Which of the following is a correct example of a Type IV (delayed) hypersensitivity reaction?

Accepted Answer

Contact dermatitis from poison ivy

Question 17

Which process is described by the following equation for antibody titer ($T$)?

$T = \frac{1}{	ext{highest dilution of serum that still gives a positive reaction}}$

Accepted Answer

Determining the strength of an immune response by measuring antibody concentration.

Question 18

Which of the following is a reason why live attenuated vaccines generally provide longer-lasting immunity than inactivated vaccines?

Accepted Answer

Live attenuated vaccines stimulate both humoral and cell-mediated immune responses.

Question 19

Which of the following is a function of NK cells?

Accepted Answer

They kill infected or abnormal cells without prior sensitization.

Question 20

Which of the following best describes the process of T cell clonal deletion?

Accepted Answer

T cells that recognize self-antigens are eliminated during development to prevent autoimmunity.

Immunology Study Guide: T Cells, Immunity, Vaccines, and Hypersensitivity

Study Guide - Practice Questions

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