Question 1

Virus infected cells secrete interferons to "warn" other cells of the presence of virus and deny entry to them.

Accepted Answer

The answer of Virus infected cells secrete interferons to "warn"...

Question 2

The directional movement of cells in response to chemicals is called chemotaxis.

Accepted Answer

Chemotaxis is defined as the directional movement of cells in response to chemicals. Therefore, the statement is true.

Question 3

Soluble proteins secreted by plasma cells are called antibodies.

Accepted Answer

Antibodies, also known as immunoglobulins, are soluble proteins that are secreted by plasma cells in response to a foreign substance (antigen) entering the body.

Question 4

The respiratory burst produced by activated macrophages releases free radicals which are effective at killing pathogens.

Accepted Answer

The respiratory burst of activated macrophages produces free radicals such as superoxide, hydrogen peroxide, and hydroxyl radicals, which help in killing pathogens. This mechanism of the immune system is critical for the destruction of invading microorganisms.

Question 5

Match the following:
-Protects mucosal barriers.
A)IgG
B)IgD
C)IgM
D)IgA
E)IgE

Accepted Answer

IgA is the immunoglobulin that protects mucosal barriers such as those in the gut, respiratory tract, and urogenital system.

Question 6

Match the following:
-Main antibody of both primary and secondary immune response.
A)IgG
B)IgD
C)IgM
D)IgA
E)IgE

Accepted Answer

IgG is the main antibody involved in both primary and secondary immune responses, providing long-term immunity and memory.

Question 7

B cells must accomplish double recognition: They must simultaneously recognize self and nonself to be activated.

Accepted Answer

B cells recognize nonself antigens through their membrane-bound immunoglobulin receptors, but they are specifically trained to not recognize self-antigens through a process called clonal deletion. Therefore, B cells only recognize nonself antigens and do not require the ability to simultaneously recognize self and nonself.

Question 8

Subacute hypersensitivities are categorically less harmful than acute (immediate)hypersensitivities.

Accepted Answer

Subacute hypersensitivities can still be harmful as they involve immune responses that can cause significant tissue damage and have a range of clinical manifestations, potentially leading to serious health issues. The severity depends on the individual case and the type of hypersensitivity, not just the speed of onset.

Question 9

Match the following:
-Along with IgM,this is a B cell receptor.
A)IgG
B)IgD
C)IgM
D)IgA
E)IgE

Accepted Answer

Along with IgM, IgD is also a B cell receptor. Both IgM and IgD are expressed on the surface of mature B cells and are involved in initiating the immune response by recognizing specific antigens.

Question 10

Dendritic cells and macrophages kill by ingestion and destruction of particulate matter in a process called phagocytosis.

Accepted Answer

Dendritic cells and macrophages are both types of immune cells that are capable of phagocytosis, which involves engulfing and destroying particulate matter such as bacteria, viruses, and cellular debris.

Question 11

Monoclonal antibodies are used in clinical laboratory diagnosis because they bind to many antigenic determinates.

Accepted Answer

Monoclonal antibodies are used because they bind to a single, specific antigenic determinant, allowing for precise targeting and identification in diagnostic tests.

Question 12

Some immunocompetent cells will never encounter an antigen to which they can bind and therefore will never be called to service in our lifetime.

Accepted Answer

It is true that some immunocompetent cells may never encounter an antigen to which they can bind, either because the antigen never enters the body or because the cells do not encounter the antigen in their lifetime. These cells may remain dormant or undergo programmed cell death without ever having the opportunity to fulfill their role in the immune system.

Question 13

Cytotoxic T cells and NK cells kill by secretion of proteins.The first called perforin which forms complexes that penetrate the cell membrane and allows the passage of the apoptosis inducing protein granzyme to enter the targeted cell.

Accepted Answer

Cytotoxic T cells and NK cells do indeed kill by secretion of proteins, including perforin and granzyme. Perforin forms complexes that penetrate the cell membrane, allowing granzyme to enter the targeted cell and induce apoptosis.

Question 14

Fever is often a beneficial immune response because it can speed the activities of leucocytes.

Accepted Answer

Fever is a beneficial immune response because it can speed up the activities of leucocytes, which are white blood cells that fight off infections and foreign particles. A fever also slows down the growth and reproduction of pathogens, making it harder for them to survive and spread. However, high fevers can be dangerous and cause other complications, so it's important to monitor and treat them appropriately.

Question 15

In a case of immediate hypersensitivity the immune system responds with an allergic response on the first exposure to the allergen.

Accepted Answer

In a case of immediate hypersensitivity, also known as type I hypersensitivity, an individual must have been previously exposed to the allergen for the immune system to mount an allergic response. The first exposure typically results in sensitization rather than an allergic reaction. It is only upon subsequent exposure to the same allergen that the immune system responds with an immediate allergic reaction.

Question 16

Viral infection will provoke cell mediated immunity but will not activate a humoral response.

Accepted Answer

While viral infections do primarily elicit a cell mediated immune response, they also activate a humoral response through the production of antibodies by B cells. Therefore, option A is incorrect.

Question 17

Anaphylactic shock is a rare but severe allergic response that may occur if the allergen enters the blood stream.

Accepted Answer

Anaphylactic shock is a rare but severe allergic response that occurs when the allergen enters the bloodstream and spreads throughout the body rapidly.

Question 18

The nucleotide sequence within the genes that produce B cell receptor and antibodies are reshuffled by a process called somatic recombination.This produces the huge variability in antibody types.

Accepted Answer

Somatic recombination is a process by which the nucleotide sequence within the genes that produce B cell receptor and antibodies are reshuffled, resulting in a vast array of possible antibody types. Therefore, the statement is true.

Question 19

Match the following:
-First to peak during a primary immune response.
A)IgG
B)IgD
C)IgM
D)IgA
E)IgE

Accepted Answer

IgM is the first antibody to be produced during a primary immune response.

Question 20

Match the following:
-Involved in allergies.
A)IgG
B)IgD
C)IgM
D)IgA
E)IgE

Accepted Answer

IgE is the immunoglobulin involved in allergies. It is responsible for triggering the release of histamine and other substances that cause allergy symptoms. IgG, IgD, IgM, and IgA are not primarily involved in allergies.

Quiz 21: The Immune System: Innate and Adaptive Body Defenses