Immune System Trivia: MCQ Test! Quiz

Explanation
An antigen is a substance that triggers an immune response in the body. When the immune system detects an antigen, it produces antibodies to neutralize or eliminate it. Antigens can be foreign substances such as bacteria, viruses, or toxins, or they can be substances produced by the body itself, such as cancer cells. The immune response triggered by antigens is an essential defense mechanism that helps protect the body against harmful invaders and maintain overall health.

Explanation
The examples of nonspecific defense listed in the answer are skin, macrophages, fever, and mucus membranes. Nonspecific defense mechanisms are the body's general ways of defending against pathogens, without targeting a specific pathogen. Skin acts as a physical barrier, preventing the entry of pathogens. Macrophages are immune cells that engulf and destroy pathogens. Fever is a response triggered by the body to inhibit the growth of pathogens. Mucus membranes, such as those in the respiratory and digestive tracts, produce mucus that traps pathogens and prevents their entry.

Explanation
A fever is a natural response of the body to fight off infections. When the body temperature rises, it can slow down the rate of chemical reactions in the body. This is because enzymes, which are responsible for speeding up chemical reactions, can be denatured or become less efficient at higher temperatures. Therefore, a fever can decrease the rate of chemical reactions in the body, allowing the immune system to focus on fighting off the infection.

Explanation
Phagocytes are a type of white blood cell that can engulf and destroy pathogens. They play a crucial role in the immune response by recognizing, engulfing, and breaking down foreign particles, such as bacteria and viruses. Antibodies are proteins produced by B-cells that specifically bind to antigens, helping to neutralize or eliminate them. Antigens are substances that can stimulate an immune response. While B-cells also play a role in the immune response by producing antibodies, they are not specifically responsible for engulfing pathogens like phagocytes.

Explanation
Antigens are proteins that bind to specific chemicals on the surface of foreign cells. They are responsible for initiating an immune response in the body. When antigens are detected, the immune system produces antibodies, which are proteins that specifically target and neutralize the antigens. Phagocytes are immune cells that engulf and destroy foreign particles, while T-cells are a type of white blood cell that plays a key role in cell-mediated immunity. However, in this context, antigens are the correct answer as they are the proteins that bind to specific chemicals on the surface of foreign cells.

Explanation
B-cells are white blood cells that produce pathogen destroying proteins called antibodies. These antibodies bind to antigens on the surface of pathogens, marking them for destruction by other immune cells. T-cells, on the other hand, are responsible for directly attacking and killing infected cells. Antigens are molecules that can trigger an immune response. Phagocytes are a type of white blood cell that engulf and destroy pathogens through a process called phagocytosis.

Explanation
A vaccine is not a small amount of a virus or bacteria. Instead, it is a biological preparation that contains either a weakened or killed form of a virus or bacteria, or a piece of the virus or bacteria. The purpose of a vaccine is to stimulate the immune system to recognize and fight against the specific virus or bacteria, without causing the actual disease. Therefore, the statement that a vaccine is a small amount of a virus or bacteria is incorrect.

Explanation
Vaccines work by stimulating the immune system to produce antibodies against a specific pathogen. When the body is exposed to the actual pathogen, the immune system recognizes it and can mount a quick and effective response, preventing the person from getting sick or reducing the severity of the illness. Therefore, the statement that vaccines allow the immune system to build up antibodies against the pathogen and protect against infection is true.

Explanation
This statement is true because allergies occur when allergens, such as pollen or pet dander, bind to mast cells in the body. When this binding occurs, the mast cells release histamine, which is a chemical that triggers allergic symptoms like sneezing, runny noses, and watery eyes. Therefore, the statement accurately explains the process of how allergies occur.

Explanation
Autoimmune diseases occur when the immune system attacks the body's own cells, not foreign cells. In these conditions, the immune system mistakenly identifies healthy cells as foreign and launches an attack against them. This can lead to inflammation, tissue damage, and various symptoms depending on the specific autoimmune disease. Therefore, the correct answer is False.