Question 1

What does seroconversion mean in relation to HIV and AIDS?
A) The virus has been identified in the blood and body fluids.
B) Antibodies for HIV have been identified in the blood.
C) HIV was found in lymphocytes.
D) Active infection has developed in the patient.

Accepted Answer

Seroconversion refers to the process where a person's blood changes from being HIV negative to HIV positive, due to the development of antibodies to the virus. This typically occurs within a few weeks to months after initial infection. Therefore, option B is the correct choice as it describes the presence of HIV antibodies in the blood. Options A, C, and D are incorrect as they do not specifically relate to the process of seroconversion.

Question 2

Tissue transferred between two genetically identical twins is referred to as a/an:
A) allograft.
B) syngraft.
C) isograft.
D) autograft.

Accepted Answer

Tissue transferred between genetically identical twins is referred to as an isograft, as the tissue is from the same individual and therefore has identical genetic material. An autograft involves transferring tissue from one part of an individual's body to another, while an allograft involves transferring tissue between two genetically different individuals. A syngraft is another term for an isograft.

Question 3

The most common cause of death in patients who have AIDS is:
A) HIV encephalopathy.
B) tuberculosis.
C) Pneumocystis carinii pneumonia.
D) Candida infection.

Accepted Answer

Pneumocystis carinii pneumonia (PCP) is the most common cause of death in patients with AIDS. PCP occurs due to a weakened immune system, making patients susceptible to infections. It often presents with fever, cough, and shortness of breath, and can be fatal if left untreated.

Question 4

Which of the following statements is TRUE regarding a patient who is HIV positive?
A) No medication is required until the CD4 cell count drops below normal range.
B) Antibodies are present, destroying the virus and preventing transmission to others.
C) Antibodies in the blood indicate presence of virus and possible transmission to others.
D) Enzymes have not yet converted RNA to DNA for replication.

Accepted Answer

Antibodies in the blood indicate the presence of the virus and possible transmission to others. HIV is a virus that attacks the immune system, specifically CD4 cells. Antibodies are produced by the immune system in response to the virus, but do not destroy the virus completely. A patient who is HIV positive can still transmit the virus to others through blood, semen, vaginal secretions, and breast milk, even if they have antibodies present. Medication is typically necessary to manage the virus and prevent it from progressing to AIDS. The CD4 cell count is an important indicator of immune function, and medication may be initiated before the count drops below the normal range in order to protect the immune system. Enzymes convert RNA to DNA for replication during the virus life cycle, but this does not affect the patient's status as HIV positive.

Question 5

Host-versus-graft disease refers to:
A) hyperacute rejection of tissue.
B) T cells in grafted tissue attacking host cells.
C) infection resulting from immunosuppression therapy.
D) transplant rejection by the recipient's immune system.

Accepted Answer

Host-versus-graft disease refers to transplant rejection by the recipient's immune system. It occurs when the recipient's immune system recognizes the transplanted tissue as foreign and launches an immune response to attack and destroy it. This can lead to tissue damage and graft failure.

Question 6

Which of the following is an effect of cytokines? They:
A) activate and stimulate proliferation of B and T lymphocytes.
B) destroy antigens quickly.
C) increase the rate of mitosis in tumors.
D) cause immediate pain.

Accepted Answer

Cytokines are signaling molecules produced by immune cells that mediate immune responses. They can activate and stimulate proliferation of B and T lymphocytes, which are involved in specific immune responses against pathogens.

Question 7

The term tolerance refers to:
A) surveillance and destruction of new cancer cells by the immune system.
B) the ability of the immune system to ignore "self" cells.
C) the ability of T and B lymphocytes to work together.
D) the role of lymphoid tissue in the body defenses.

Accepted Answer

Tolerance refers to the ability of the immune system to recognize and tolerate "self" cells and molecules, while still being able to identify and mount a response against potential pathogens or foreign substances. This helps to prevent autoimmune diseases where the immune system attacks the body's own cells and tissues.

Question 8

CD4-positive helper T cells function by:
A) direct cytotoxic action.
B) facilitating all immune system activity.
C) producing immunoglobulins.
D) inactivating allergens.

Accepted Answer

CD4-positive helper T cells play a critical role in facilitating immune system activity by assisting in the activation and proliferation of other immune cells such as B cells and cytotoxic T cells. They do not have direct cytotoxic action, produce immunoglobulins, or inactivate allergens.

Question 9

Which of the following complications does NOT occur frequently in AIDS patients?
A) Kaposi's sarcoma
B) Wasting syndrome
C) Lymphoma
D) Polyarthritis

Accepted Answer

Polyarthritis is not a frequent complication in AIDS patients. Kaposi's sarcoma, wasting syndrome, and lymphoma are all common complications in AIDS patients.

Question 10

Which of the following characteristics apply to HIV?
1) It contains two strands of DNA.
2) It tends to mutate frequently to form new strains.
3) The incubation period is extremely short.
4) It is inactivated by heat and many disinfectants.
A) 1, 2
B) 1, 3
C) 2, 4
D) 3, 4

Accepted Answer

HIV contains a single strand of RNA, not DNA (statement 1 is incorrect). It is known to mutate frequently, leading to the formation of new strains (statement 2 is correct). The incubation period for HIV can range from months to years, making it a relatively long incubation period (statement 3 is incorrect). HIV is inactivated by heat and many disinfectants, making it relatively susceptible to environmental interventions (statement 4 is correct). Therefore, only statements 2 and 4 are accurate.

Question 11

Which of the following statements applies to the complement system?
A) It is activated by IgE.
B) It blocks the inflammatory response.
C) It consists of proteins in the blood that must be activated.
D) It may destroy antibodies in the circulation.

Accepted Answer

The complement system consists of proteins in the blood that must be activated in order to function. It plays a role in both innate and adaptive immunity, and can initiate inflammation or directly destroy pathogens. None of the other statements are correct - IgE activates mast cells and basophils, not the complement system; the complement system can actually promote inflammation; and it does not destroy antibodies in the circulation.

Question 12

In cases of HIV infection, the "window period" refers to the time between:
A) entry of the virus into the blood and the initial manifestations.
B) entry of the virus into the body and the appearance of antibodies in the blood.
C) entry of the virus into the body and a significant drop in CD4 T-helper lymphocyte count.
D) diagnosis of "HIV positive" and diagnosis of "AIDS."

Accepted Answer

The window period in HIV infection refers to the time between the entry of the virus into the body and the appearance of antibodies in the blood, which can take several weeks to months. During this period, an individual may test negative for HIV even though they are infected because their body has not produced detectable levels of antibodies yet. It is important to note that HIV can still be transmitted during the window period, so precautions should be taken to prevent the spread of the virus.

Question 13

Which of the following is NOT a cause of immunodeficiency?
A) Hypoplasia of the thymus
B) Delayed hypersensitivity
C) Immunosuppressive drugs
D) Atrophy of the lymph nodes

Accepted Answer

Delayed hypersensitivity is not a cause of immunodeficiency. In fact, it is a type of immune response that involves T cells and is important in fighting certain infections and in delayed-type allergic reactions. The other three choices (A, C, and D) all involve structural or functional changes in the immune system that can lead to immunodeficiency.

Question 14

Which statement is TRUE regarding infants born to HIV-infected mothers?
A) Infants usually test negative for HIV after birth.
B) There is little risk of infected mothers passing the virus to their infants during delivery.
C) Breast milk does not contain HIV or antibodies.
D) Infants test positive for HIV because of the presence of maternal antibodies.

Accepted Answer

Infants born to HIV-infected mothers will test positive for HIV due to the presence of maternal antibodies, but this does not necessarily mean that they are infected with the virus. It can take up to 18 months for the maternal antibodies to leave the infant's bloodstream, so additional testing is needed to confirm whether the infant is truly infected or not. Additionally, there is a risk of transmission of the virus from infected mothers to their infants during childbirth or through breast milk. However, with proper medical treatment and interventions, the risk of transmission can be greatly reduced.

Question 15

Which of the following statements regarding immunoglobulins is TRUE?
A) They consist of a unique sequence of amino acids.
B) They are produced in the red bone marrow.
C) They are attached to mucosal membranes at entry points into the body.
D) IgA binds to allergens.

Accepted Answer

The answer of Which of the following statements regarding immunoglobulins...

Quiz 7: Immunity

What does seroconversion mean in relation to HIV and AIDS?

Tissue transferred between two genetically identical twins is referred to as a/an:

The most common cause of death in patients who have AIDS is:

Which of the following statements is TRUE regarding a patient who is HIV positive?

Host-versus-graft disease refers to:

Which of the following is an effect of cytokines? They:

The term tolerance refers to:

CD4-positive helper T cells function by:

Which of the following complications does NOT occur frequently in AIDS patients?

Which of the following characteristics apply to HIV? 1) It contains two strands of DNA. 2) It tends to mutate frequently to form new strains. 3) The incubation period is extremely short. 4) It is inactivated by heat and many disinfectants.

Which of the following statements applies to the complement system?

In cases of HIV infection, the "window period" refers to the time between:

Which of the following is NOT a cause of immunodeficiency?

Which statement is TRUE regarding infants born to HIV-infected mothers?

Which of the following statements regarding immunoglobulins is TRUE?