Checkpoints occur between the stages of the cell cycle. If a cell does not meet certain criteria at the end of a stage, it will not move to the next stage. Which of these occurs just before the cell enters the G2 stage of the cell cycle?

DNA replicates
DNA replicates

The cell divides
The cell divides

Vacuoles form
Vacuoles form

The nuclear membrane disintegrates

How do diseases caused by bacteria and diseases caused by viruses react to antibiotics?

When lactate builds up in a runners muscles it causes a burning sensation what causes this to occur

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.