The kingdom described in "the lady, or the tiger?" is _____.

To stay abstinent, one should __________.

Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.

Human body cells are approximately ______ water.

The gill flap, or operculum, was an important adaptation for fish because it helps with __________.

_____ describes why similar organisms do not interbreed because of a physical barrier.

The opening of stomata is thought to involve _____.

The rate with which an action potential travels along an axon _______.

Associative long-term potentiation reflects increased ________ produced by changes in ________.

In areolar connective tissue, ________ cells release histamine.

In skeletal muscle, the term that describes the alternating light and dark bands is ___________.