During exercise, cardiac output may increase by more than 170% to meet the body's increased o2 demands. this increase in cardiac output increases blood pressure. but the accompanying increase in arterial pressure is relatively small—only about 40%. what limits this increase in blood pressure so that it doesn't reach dangerously high levels during exercise?

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.