Final answer:
Allergy to pollen is classified as immediate hypersensitivity (Type I Hypersensitivity), leading to quick immune reactions upon exposure after sensitization. Common allergens include pollen, triggering symptoms like watery eyes and sneezing. These reactions are not protective, as the allergens are usually harmless.
Step-by-step explanation:
Allergy to pollen is classified as d. immediate hypersensitivity. This type of allergic reaction is referred to as Type I Hypersensitivity. It occurs when an individual's immune system overreacts to a harmless protein in the environment, such as pollen, leading to an inflammatory response. During the first exposure to an allergen, the immune system produces Immunoglobulin E (IgE) antibodies. These IgE antibodies sensitize the body, so upon subsequent exposures, they trigger a swift immune response that can result in various symptoms, including watery eyes, itching, and sneezing.
Common allergens that can provoke such reactions include plant pollen, which can cause allergic rhinitis or hay fever, animal dander, certain foods like peanuts, and insect venom, among others. Unlike helpful immune responses that protect the body against harmful pathogens, allergies are considered non-protective immune responses because they target substances that are typically harmless and cause unpleasant symptoms.