Living Environment Regents Practice Test 2026 – Complete Exam Prep

The immune response to non-threatening substances is termed an allergy. Allergies occur when the immune system mistakenly identifies a harmless substance, such as pollen, peanuts, or pet dander, as a harmful pathogen. This triggers an exaggerated immune response, including the production of antibodies, particularly Immunoglobulin E (IgE), which leads to the release of histamines and other chemicals that cause allergic symptoms like sneezing, itching, and swelling.

In contrast, a pathogen response specifically refers to the immune response aimed at attacking harmful organisms like viruses or bacteria. An autoimmune reaction involves the immune system mistakenly attacking the body's own cells, leading to conditions such as lupus or rheumatoid arthritis. The inflammatory response, while it can occur in response to allergies, is a more general reaction that occurs as part of the immune system's defense mechanisms against various types of injury or infection.