Question 1

Which antibody class is most responsible for the allergic reaction?

Accepted Answer

IgE is the antibody class most responsible for the allergic reaction. When an allergen enters the body, it triggers the production of IgE antibodies which bind to mast cells and basophils. Upon re-exposure to the allergen, the IgE antibodies on these cells bind to the allergen, causing the release of histamine and other inflammatory mediators, leading to the symptoms of an allergic reaction.

Question 2

Which T cell boosts the immune response by activating other types of cells?

Accepted Answer

Helper T cells, also known as CD4+ T cells, play a critical role in the immune response by activating and coordinating other immune cells, such as B cells and cytotoxic T cells. They do this by releasing cytokines and other signaling molecules that stimulate these cells to perform their functions.

Question 3

If you are bitten by a highly venomous snake, you would need to be given antivenom right away. Antivenom is made from injecting horses with small-to-larger dosages of snake venom, and then harvesting the antibodies from the horse plasma. Antivenom is an example of

Accepted Answer

Antivenom is an example of passive immunity because it involves the direct transfer of pre-formed antibodies from another organism (horse) rather than stimulating the recipient's immune system to produce their own antibodies (active immunity).

Question 4

Which type of lymphocyte is sometimes called a "killer cell" because it brings about destruction of cells bearing a specific non-cell protein?

Accepted Answer

Cytotoxic T cells are responsible for identifying and destroying cells that display specific non-cell proteins, such as virus-infected or cancerous cells. This is why they are sometimes called "killer cells". Helper T cells help activate and coordinate other immune system cells, suppressor T cells regulate immune responses, and memory T cells "remember" previously encountered pathogens for a faster response upon future exposure. Macrophages are also immune cells that help engulf and destroy foreign substances.

Question 5

When a person is bitten by a venomous snake, receiving blood plasma from another person who recently survived the same type of snake bite would provide passive immunity.

Accepted Answer

Blood plasma from a person who recently survived the same type of snake bite would contain antibodies against the venom, providing passive immunity to the person who was bitten.

Question 6

Cytokines may be used in the treatment of cancer and AIDS because they stimulate white blood cell formation and/or function.

Accepted Answer

Cytokines, such as interleukins and interferons, have been used in the treatment of cancer and AIDS due to their ability to enhance the immune system's response to these diseases by stimulating white blood cell production and activity.

Question 7

What blood type is considered the universal donor?

Accepted Answer

Blood type O is considered the universal donor because it lacks A and B antigens on its red blood cells, making it compatible with all blood types.

Question 8

A vaccine contains

Accepted Answer

Vaccines contain antigens that are no longer virulent, meaning they are either inactivated or weakened forms of the pathogen. This allows the body to recognize and create an immune response to the pathogen without causing the disease itself. Penicillin, horse serum, and antibiotics are not used in vaccines. Antibodies made by plasma cells are part of the body's immune response, but are not typically included in vaccines.

Question 9

Cowpox is very similar to smallpox, which is more dangerous for humans. Edward Jenner promoted the use of cowpox as a vaccination to provide patients immunity from future smallpox epidemics. Patients given cowpox developed

Accepted Answer

Patients given cowpox developed active immunity, as their own immune systems were stimulated to produce antibodies and memory cells to protect against future infections.

Question 10

A response that does not occur immediately cannot be considered an allergic response, even if it appears like one.

Accepted Answer

Allergic responses can be immediate or delayed, with some reactions occurring hours to days after exposure to an allergen.

Question 11

The primary target of the HIV virus is

Accepted Answer

The HIV virus primarily targets and infects helper T cells, which play a critical role in the immune response against infections. The virus uses the CD4 receptor on the surface of these cells to gain entry and then replicates inside, eventually leading to their destruction and a weakened immune system.

Question 12

An antibody will react against any virus or bacterial cell.

Accepted Answer

An antibody is specific to a particular virus or bacterial cell. It will only react against that specific microbe or a closely related strain of it.

Question 13

In order to prevent an allergic reaction, injections of the allergen are sometimes given.

Accepted Answer

This technique is called immunotherapy and involves gradually exposing the individual to increasing amounts of the allergen to build up tolerance and reduce the severity of allergic reactions. It is a common treatment for allergies such as hay fever, insect sting allergies, and some types of food allergies.

Question 14

Anaphylactic shock may occur due to

Accepted Answer

Anaphylactic shock is a severe allergic reaction that can occur in response to certain allergens, such as bee stings, certain foods, or medications. Option A is incorrect because exposure to HIV does not cause anaphylactic shock. Option C is incorrect because organ donation is a medical procedure that does not generally cause anaphylactic shock. Option D is incorrect because interferon is a medication used to treat certain medical conditions and is not a known cause of anaphylactic shock. Option E is incorrect because antihistamines are actually used to treat and prevent allergic reactions such as anaphylaxis.

Question 15

Which of the following statements is true about hemolytic disease of the newborn?

Accepted Answer

Hemolytic disease of the newborn occurs when there is an incompatibility between the blood types of the mother and fetus, such as when an Rh-negative mother (Rh^-) carries an Rh-positive baby (Rh⁺), potentially leading to the mother's immune system attacking the fetus's red blood cells.

Question 16

Babies generally appear to be immune to diseases for approximately the first six months of life. What could be responsible for this immunity?

Accepted Answer

Babies are born with a certain level of immunity that they acquire from their mothers, which is called passive immunity. This immunity is obtained from the transfer of antibodies from the mother via the placenta during pregnancy and from breast milk after birth. This passive immunity provides protection to infants until their own immune systems develop fully, which takes about six months.

Question 17

A person who is B positive will have

Accepted Answer

A person who is B positive will have B antigens, anti-A antibody, and Rh antigen. Option A is incorrect because it describes a person who is A positive. Option B describes a person who is O positive. Option C describes a person who is B negative. Option E describes a person who is B positive but does not have Rh antigen.

Question 18

Which of the following is true regarding monoclonal antibodies?

Accepted Answer

All of the answer choices are correct. Monoclonal antibodies are produced from a single type of plasma cell and can be produced in vitro by fusing spleen cells with malignant plasma cells. They are used in the diagnosis and treatment of various diseases.

Question 19

In the later 1800s, the brilliant French chemist Louis Pasteur worked with chicken cholera, passing the disease agent from sick to healthy chickens. He suspended his research and went on vacation for several weeks. When he returned, the old cholera culture he gave to healthy chickens failed to kill them. He assumed his culture was bad and injected these same chickens with a fresh culture of chicken cholera. These chickens remained healthy while new chickens injected with the fresh culture of chicken cholera rapidly became sick and died. From our current knowledge of immunity, how would these observations be explained?

Accepted Answer

The first disease culture had weakened over time and stimulated the development of active immunity. The chickens that were previously exposed to the weakened culture had already developed immunity to the disease, so when they were injected with the fresh culture, their immune system was able to fight off the infection. This is an example of acquired active immunity, where the body's immune system has been activated to produce specific antibodies in response to an antigen.

Question 20

A person who is blood type AB has

Accepted Answer

Blood type AB has antigens A and B on the surface of RBCs, but no antibodies on the surface. This is because individuals with blood type AB have both A and B alleles, which encode for the enzymes needed to produce both antigens on the surface of their RBCs. Therefore, they can receive blood from individuals with any ABO blood type without experiencing an adverse reaction.

Quiz 13: Lymphatic and Immune Systems