Question

An allergic reaction is "a hypersensitive response of the immune system to a foreign substance." This reaction can occur when the immune system attacks a normally harmless substance (the allergen). Yes or No ?

Answer 1

An allergic reaction occurs when the immune system mistakenly reacts to a harmless substance, causing symptoms like sneezing and itching.

Step-by-step explanation:

An allergic reaction occurs when the immune system mistakenly identifies a harmless substance, known as an allergen, as a threat and mounts an immune response. This immune response can cause a variety of symptoms, such as sneezing, itching, or swelling.

For example, if someone with a pollen allergy inhales pollen particles, their immune system may mistakenly identify the pollen as a harmful invader and release chemicals, such as histamine, to defend against it. This can lead to symptoms like sneezing, runny nose, and itchy eyes.