When an experiment is repeated and the new results are different from the original results, what could you assume to be true?
a) the first set of results must be incorrect and thrown out.
b) the second set of results must be inaccurate and thrown out.
c) the experimental design must be flawed and should be scrapped.
d) the original experiment may be inaccurate and further experimentation is needed.

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.