A student enters the museum and observes the animal specimens. He looks at the one marked whale and calls it a type offish. How will you explain to him that whale and fishes belong to two different classes ? List any three distinguishing features to justi

A student enters the museum and observes the animal specimens. He looks at the one marked whale and calls it a type offish. How will you explain to him that whale and fishes belong to two different classes ? List any three distinguishing features to justify your statement.