Immunology And Immune System Questions And Answers

Explanation
Macrophages are immune cells that play a crucial role in identifying and eliminating foreign substances in the body. They have the ability to recognize antigens, which are molecules present on the surface of cells or pathogens that trigger an immune response. Macrophages can detect these antigens and initiate an immune response by engulfing and destroying the foreign substances. Therefore, the correct answer to this question is antigens.

Explanation
Red blood cells are not part of the body's immune response. They are responsible for carrying oxygen to the body's tissues and removing carbon dioxide. Immune responses are mediated by cells such as B cells, macrophages, and lymphocytes, which play roles in recognizing and eliminating pathogens and foreign substances.

Explanation
Antibodies are a crucial part of the body's specific defenses. They are proteins produced by the immune system in response to the presence of foreign substances, such as bacteria or viruses. Antibodies recognize and bind to these foreign substances, marking them for destruction by other immune cells. This targeted response helps to eliminate the specific threat and prevent further infection or illness. Macrophages, inflammation, and mucus production are also important defense mechanisms, but antibodies play a specific role in identifying and neutralizing foreign invaders.

Explanation
T cells are responsible for activating B cells in the immune response. When a pathogen enters the body, T cells recognize and bind to the antigens on the surface of the pathogen. This interaction triggers the activation of B cells, which then produce antibodies to target and neutralize the pathogen. Therefore, T cells alert B cells to take action against the invading pathogen. Antibodies are produced by B cells, red blood cells are not directly involved in immune responses, and inflammation is a response to tissue damage or infection, but it does not specifically alert B cells to action.

Explanation
B cells are responsible for producing antibodies. When a foreign substance, known as an antigen, enters the body, B cells recognize it and produce specific antibodies to target and neutralize the antigen. These antibodies bind to the antigen, marking it for destruction by other immune cells. B cells are a crucial part of the adaptive immune response, as they can remember previous encounters with antigens and mount a faster and more effective response upon reinfection. T cells, on the other hand, play a different role in the immune response, primarily involved in recognizing and directly attacking infected cells. Macrophages are responsible for engulfing and destroying pathogens, but they do not directly produce antibodies.

Explanation
An injection of preformed antibodies produces passive immunity. Passive immunity occurs when antibodies are transferred from one individual to another, providing immediate protection against a specific pathogen. This type of immunity does not require the recipient's immune system to produce its own antibodies, hence the term "passive." It is a temporary form of immunity that can be obtained through sources such as maternal antibodies, immune serum, or monoclonal antibodies.

Explanation
A vaccine produces active immunity. This means that the vaccine stimulates the immune system to produce an immune response, including the production of antibodies and memory cells. These memory cells can recognize and respond to the specific pathogen if encountered again in the future, providing long-term protection against the disease. Active immunity is different from passive immunity, where pre-formed antibodies are transferred from another source, such as through maternal transfer or administration of immune globulins.

Explanation
Fever is a part of the body's nonspecific defenses because it is a natural response to infection or illness. It is triggered by the release of chemicals called pyrogens, which raise the body's temperature to help fight off pathogens. Fever helps to enhance the immune response by increasing the production of white blood cells, speeding up the body's healing process, and creating an unfavorable environment for bacteria and viruses to thrive. Therefore, fever is an important defense mechanism that helps the body combat infections and maintain overall health.

Explanation
Eosinophils are a type of white blood cell that play a crucial role in the immune response against parasites. They release toxic substances, such as enzymes and proteins, that can kill large parasites extracellularly. Eosinophils are particularly effective against helminths, which are large parasites like worms. By targeting and attacking these parasites, eosinophils help to eliminate the threat and protect the body from infection.

Explanation
Passive immunization is done for diphtheria, tuberculosis, and enteric fever. This means that in passive immunization, preformed antibodies are directly given to an individual to provide immediate protection against these diseases. Therefore, the correct answer is "All of the above."