Most mutagens are carcinogens. this is because __________.

Much of the original forest cover on madagascar has been destroyed primarily as a result of _____.

Natural selection drives changes in allele frequencies by influencing traits with a ____ basis.

Negative feedback is a method of homeostatic control that __________.

Nodes of _____ are gaps in the _____ that coat some axons.

Rods are to cones as _____ is (are) to _____.

Of all the flexor muscles of the forearm, the __________ is the shortest.

Myelinated fibers (tracts) form ________ matter while unmyelinated fibers form ________ matter.

A polysynaptic reflex has at least ________ in the reflex pathway.

The frequency of cystitis in men is lower than in women because ______.

The region of thin filaments only that is part of two adjacent sarcomeres is the ______.