Question

An allergy is a hypersensitivity to substances that are essentially harmless. For as yet poorly understood reasons, the immune system malfunctions and marshals up an army of antibodies to fight these substances. For many allergies, this malfunction causes a large amount of histamine to flood into the bloodstream. It is overabundance of histamine that causes allergic symptoms such as headaches, rashes, and sneezing. The passage states all of the following about allergies EXCEPT?

A) Allergies result from immune system malfunction
B) Histamine is a key factor in allergic symptoms
C) Allergies are well-understood by medical professionals
D) Allergies involve hypersensitivity to harmless substances

Answer 1

The passage does not state that allergies are well-understood by medical professionals; it asserts that allergies result from an immune system malfunction, involves an overproduction of histamine, and are responses to harmless substances.

Step-by-step explanation:

The passage states several facts about allergies, including that they result from an immune system malfunction, histamine is a key factor in allergic symptoms, and allergies involve hypersensitivity to harmless substances. However, the passage does not state that allergies are well-understood by medical professionals, which is the correct answer to the question of what the passage does not say about allergies. Allergies are hypersensitivities to substances that are commonly harmless, triggered by the immune system's overreaction to these substances known as allergens. This malfunction leads to the production of antibodies and a release of histamine into the bloodstream, which causes symptoms such as headaches, rashes, and sneezing. Despite the knowledge about these processes, the exact reasons behind the immune system's overreaction remain poorly understood.