Best friends form primary groups.

When can ethnocentrism be functional for a society?

Nematode worms and annelid worms share which of the following features?  

Which of these are amniotes?

Which of the following combinations of phylum and description is incorrect?  

Which of the following would not be located in the CNS?

Recruiting more motor units in a muscle results in greater force production by that muscle.

Acetylcholine is released by all somatic motor neurons, all preganglionic neurons of the ANS and by the postganglionic parasympathetic nerve fibers.

During muscle contraction, cross bridges form when myosin heads attach to active sites located on ________.

Which of the following does NOT describe the ANS?