Immunology Exam 1 Practice Questions
& Answers
1. A previously healthy 8-year-old boy is infected with an upper respiratory tract virus for
the first time. During the first few hours of infection, which one of the following events
occurs?
a. The adaptive immune system responds rapidly to the virus and keeps the viral
infection under control.
b. The innate immune system responds rapidly to the viral infection and keeps the viral
infection under control.
c. Passive immunity mediated by maternal antibodies limits the spread of infection.
d. B and T lymphocytes recognize the virus and stimulate the innate immune response.
e. The virus causes malignant transformation of respiratory mucosal epithelial cells, and
the malignant cells are recognized by the adaptive immune system. - ANSWER-Correct
answer: B
The innate immune response to microbes develops within hours of infection, well before
the
adaptive immune response. B and T lymphocytes are components of the adaptive
immune
response, and they would not be able to respond to a newly encountered virus before
the innate immune response. An 8-year-old boy would no longer have maternal
antibodies from transplacental passive transfer and is unlikely to be breast-feeding,
which is another potential source of maternal antibodies. Malignant transformation takes
months or years to develop.
2. Which of the following is a unique property of the adaptive immune system?
a. Highly diverse repertoire of specificities for antigens
b. Self-nonself discrimination
c. Recognition of microbial structures by both cell-associated and soluble receptors
,d. Protection against viral infections
e. Responses that have the same kinetics and magnitude on repeated exposure to the
same microbe - ANSWER-Correct: A
Highly diverse repertoires of specificities for antigens are found only in T and B
lymphocytes, which are the central cellular components of the adaptive immune system.
Both the innate and the adaptive immune systems use cell-associated and soluble
receptors to recognize microbes, display some degree of self-nonself discrimination,
and protect against viruses. On repeated exposure to the same microbe, the adaptive
immune response becomes more rapid and of greater magnitude, this is the
manifestation of memory.
3. A standard treatment of animal bite victims, when there is a possibility that the animal
was infected with the rabies virus, is administration of human immunoglobulin
preparations containing anti-rabies virus antibodies. Which type of immunity would be
established by this treatment?
a. Active humoral immunity
b. Passive humoral immunity
c. Active cell-mediated immunity
d. Passive cell-mediated immunity
e. Innate immunity - ANSWER-Correct: B
Humoral immunity is mediated by antibodies. The transfer of protective antibodies made
by one or more individuals into another individual is a form of passive humoral
immunity. Active immunity to an infection develops when an individual's own immune
system responds to the microbe. Cell-mediated immunity is mediated by T lymphocytes,
not antibodies, and innate immunity is not mediated by either antibodies or T
lymphocytes.
4. At 15 months of age, a child received a measles-mumps-rubella vaccine (MMR). At
age 22, she is living with a family in Mexico that has not been vaccinated and she is
exposed to measles. Despite the exposure, she does not become infected. Which of the
following properties of the adaptive immune system is best illustrated by this scenario?
a. Specificity
b. Diversity
c. Specialization
, d. Memory
e. Nonreactivity to self - ANSWER-Correct: D
Protection against infections after vaccination is due to immunologic memory of the
adaptive immune system. Memory is manifested as a more rapidly developing and
vigorous response on repeat exposure to an antigen compared with the first exposure.
Specificity and diversity are properties related to the range of antigenic structures
recognized by the immune system, and specialization is the ability of the adaptive
immune system to use distinct effector mechanisms for distinct infections.
5. The two major functional classes of effector T lymphocytes are
a. Helper T lymphocytes and cytotoxic T lymphocytes
b. Natural killer cells and cytotoxic T lymphocytes
c. Memory T cells and effector T cells
d. Helper cells and antigen-presenting cells
e. Cytotoxic T lymphocytes and target cells - ANSWER-Correct: A
T cells can be classified into effector subsets that perform different effector functions.
Most effector T cells are either helper T lymphocytes, which promote macrophage and
B cell responses to infections, or cytotoxic T lymphocytes, which directly kill infected
cells. Natural killer cells are not T lymphocytes. Antigen-presenting cells usually are not
T cells. Memory T cells are not effector T cells.
6. Which of the following best describes clonal expansion in adaptive immune
responses?
a. Increased number of different lymphocyte clones, each clone specific for a different
antigen during the course of an infection
b. Increased number of different lymphocyte clones, each clone specific for a different
antigen during development of the immune system, before exposure to antigen
c. Increased number of lymphocytes with identical specificities, all derived from a single
lymphocyte due to nonspecific stimuli from the innate immune system
d. Increased number of lymphocytes with identical specificities, all derived from a single
lymphocyte stimulated by a single antigen
e. Increased size of the lymphocytes of a single clone due to antigen-induced activation
of the cells - ANSWER-Correct: D
& Answers
1. A previously healthy 8-year-old boy is infected with an upper respiratory tract virus for
the first time. During the first few hours of infection, which one of the following events
occurs?
a. The adaptive immune system responds rapidly to the virus and keeps the viral
infection under control.
b. The innate immune system responds rapidly to the viral infection and keeps the viral
infection under control.
c. Passive immunity mediated by maternal antibodies limits the spread of infection.
d. B and T lymphocytes recognize the virus and stimulate the innate immune response.
e. The virus causes malignant transformation of respiratory mucosal epithelial cells, and
the malignant cells are recognized by the adaptive immune system. - ANSWER-Correct
answer: B
The innate immune response to microbes develops within hours of infection, well before
the
adaptive immune response. B and T lymphocytes are components of the adaptive
immune
response, and they would not be able to respond to a newly encountered virus before
the innate immune response. An 8-year-old boy would no longer have maternal
antibodies from transplacental passive transfer and is unlikely to be breast-feeding,
which is another potential source of maternal antibodies. Malignant transformation takes
months or years to develop.
2. Which of the following is a unique property of the adaptive immune system?
a. Highly diverse repertoire of specificities for antigens
b. Self-nonself discrimination
c. Recognition of microbial structures by both cell-associated and soluble receptors
,d. Protection against viral infections
e. Responses that have the same kinetics and magnitude on repeated exposure to the
same microbe - ANSWER-Correct: A
Highly diverse repertoires of specificities for antigens are found only in T and B
lymphocytes, which are the central cellular components of the adaptive immune system.
Both the innate and the adaptive immune systems use cell-associated and soluble
receptors to recognize microbes, display some degree of self-nonself discrimination,
and protect against viruses. On repeated exposure to the same microbe, the adaptive
immune response becomes more rapid and of greater magnitude, this is the
manifestation of memory.
3. A standard treatment of animal bite victims, when there is a possibility that the animal
was infected with the rabies virus, is administration of human immunoglobulin
preparations containing anti-rabies virus antibodies. Which type of immunity would be
established by this treatment?
a. Active humoral immunity
b. Passive humoral immunity
c. Active cell-mediated immunity
d. Passive cell-mediated immunity
e. Innate immunity - ANSWER-Correct: B
Humoral immunity is mediated by antibodies. The transfer of protective antibodies made
by one or more individuals into another individual is a form of passive humoral
immunity. Active immunity to an infection develops when an individual's own immune
system responds to the microbe. Cell-mediated immunity is mediated by T lymphocytes,
not antibodies, and innate immunity is not mediated by either antibodies or T
lymphocytes.
4. At 15 months of age, a child received a measles-mumps-rubella vaccine (MMR). At
age 22, she is living with a family in Mexico that has not been vaccinated and she is
exposed to measles. Despite the exposure, she does not become infected. Which of the
following properties of the adaptive immune system is best illustrated by this scenario?
a. Specificity
b. Diversity
c. Specialization
, d. Memory
e. Nonreactivity to self - ANSWER-Correct: D
Protection against infections after vaccination is due to immunologic memory of the
adaptive immune system. Memory is manifested as a more rapidly developing and
vigorous response on repeat exposure to an antigen compared with the first exposure.
Specificity and diversity are properties related to the range of antigenic structures
recognized by the immune system, and specialization is the ability of the adaptive
immune system to use distinct effector mechanisms for distinct infections.
5. The two major functional classes of effector T lymphocytes are
a. Helper T lymphocytes and cytotoxic T lymphocytes
b. Natural killer cells and cytotoxic T lymphocytes
c. Memory T cells and effector T cells
d. Helper cells and antigen-presenting cells
e. Cytotoxic T lymphocytes and target cells - ANSWER-Correct: A
T cells can be classified into effector subsets that perform different effector functions.
Most effector T cells are either helper T lymphocytes, which promote macrophage and
B cell responses to infections, or cytotoxic T lymphocytes, which directly kill infected
cells. Natural killer cells are not T lymphocytes. Antigen-presenting cells usually are not
T cells. Memory T cells are not effector T cells.
6. Which of the following best describes clonal expansion in adaptive immune
responses?
a. Increased number of different lymphocyte clones, each clone specific for a different
antigen during the course of an infection
b. Increased number of different lymphocyte clones, each clone specific for a different
antigen during development of the immune system, before exposure to antigen
c. Increased number of lymphocytes with identical specificities, all derived from a single
lymphocyte due to nonspecific stimuli from the innate immune system
d. Increased number of lymphocytes with identical specificities, all derived from a single
lymphocyte stimulated by a single antigen
e. Increased size of the lymphocytes of a single clone due to antigen-induced activation
of the cells - ANSWER-Correct: D
