Which of the following statements best describes what happens during exercise ? a) blood vessels in the muscles dilate to increase blood flow b) blood vessels in the lungs dilate to increase blood volume c) blood vessels in the heart dilate to increase blood pressure d) blood vessels in the organs dilate to increase blood oxygen

An easy way to calculate the amount of energy available at each level is to what?

Mike has a problem with his testosterone. he is unable to produce enough. which will most likely be affected by his inability to produce testosterone? check all that apply.

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.