What is the problem with the design of the following experiment? sandra has three dogs: a husky, a golden retriever, and a chihuahua. she wonders what types of food dogs like the most. she feeds the husky and golden retriever a bowl of fish flavored dog food in the morning. then she takes them on a long walk and feeds them chicken flavored dog food for lunch. then they rest at home for the afternoon, and she feeds them beef flavored dog food for dinner. she feeds the chihuahua a cheeseburger for every meal.

Female luna moths (actias luna) attract males by emitting chemical signals that spread through the air. a male hundreds of meters away can detect these molecules and fly toward their source. the sensory organs responsible for this behavior are the comblike antennae visible in the photograph shown here. each filament of an antenna is equipped with thousands of receptor cells that detect the sex attractant. based on what you learned in this chapter, propose a hypothesis to account for the ability of the male moth to detect a specific molecule in the presence of many other molecules in the air. what predictions does your hypothesis make? design an experiment to test one of these predictions.