A student on a school trip started sneezing and wheezing soon after reaching the hill station for no explaied reasons. But, on return to the plains, the symptoms disappeared. What is such a response called? How does the body produce it?

When one goes to a new place and suddenly starts sneezing and wheezing for no explained reason and then these sympotms disappear when one returns. This condition is called

A student on a school picnic to a park on a windy day started sneezing and having difficulty in breathing on reaching the park. The teacher enquired whether the student was allergic to something. (a) What is an allergy? (b) Write the two unique charactristics of the system involved in the response observed in the student.