6. Temperatures have been rising since , but the is increasing. Options:
a. The beginning of the Pleistocene; rate of increase
b. Earth began; rate of decrease
c. Plants evolved; rate of decrease
d. The end of the Pleistocene; rate of increase

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

Which of the following forest management practices is best for reestablishing areas of forest?

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.