Biology Pak 9 Self Check Quiz 4

Explanation
Remember that the first line of defense is very general.

Explanation
The inflammatory response is a nonspecific defense mechanism against pathogens. When the body detects an injury or infection, it releases chemicals that cause blood vessels to dilate and become more permeable. This allows immune cells and substances to quickly reach the affected area, promoting healing and preventing the spread of pathogens. The inflammatory response is a general defense mechanism that occurs regardless of the specific pathogen involved, making it a nonspecific defense. B cells, helper T cells, and antibodies, on the other hand, are part of the specific immune response, targeting specific pathogens.

Explanation
An antibody is a Y-shaped molecule that is produced by plasma cells upon exposure to a specific antigen and can bind to that antigen. Antibodies are a crucial part of the immune response, as they help to neutralize pathogens and activate other immune cells to eliminate the threat. Macrophages, B cells, and helper T cells are all important components of the immune system, but they do not specifically refer to the Y-shaped molecule that can bind to antigens.

Explanation
HIV causes AIDS by attacking and destroying helper T cells. Helper T cells play a crucial role in the immune system by coordinating the response to infections. When HIV infects helper T cells, it weakens the immune system and makes it difficult for the body to fight off infections and diseases. As a result, individuals with AIDS become more susceptible to opportunistic infections and other complications.

Explanation
An inappropriate immune system response against a nonpathogenic antigen is called an allergic reaction. This occurs when the immune system overreacts to a harmless substance, such as pollen or certain foods, and triggers a response that can cause symptoms like sneezing, itching, and inflammation. Unlike autoimmune diseases, which involve the immune system attacking the body's own cells and tissues, allergic reactions are a response to external substances.

Explanation
Vaccines are effective in preventing disease because they trigger antibody formation. When a vaccine is administered, it contains harmless fragments or weakened forms of the pathogen. This stimulates the immune system to recognize the pathogen as foreign and produce antibodies against it. These antibodies are then able to recognize and neutralize the actual pathogen if the individual is later exposed to it, preventing the development of the disease. By triggering antibody formation, vaccines provide a specific and targeted immune response that can protect against future infections.