which statement best describes how a muscle moves a bone?
tendons connect extensions and flexors to move the bone.
flexors cause the bone to move in both direction.
the muscle pulls on the insertion point on the bone.
extensors cause the bones to move in both direction.

The graph shows the solubility of several different salts in water, across a range of temperatures. according to the graph, which salt can dissolve at a concentration of about 60 g/100 cm3 of water at 40 degrees celsius?

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.

What happens when two nitrogen atoms share electrons