When hyperpolarization occurs, the transmembrane potential…

Neurons that have two axons extending off on either side of the cell body are called

In the resting neuron, _____ channels allow a small amount of Na+ and Ka+ to pass into and out of the cell along their concentration gradients.

Bones play a central role in the regulation of blood levels of

What type of channels are found on the dendrites and cell body of the neuron and are associated with graded (local) potentials?

Which one of the following is true about graded potentials?

________________ is the first level of organization that is alive.

What was a major morphological criterion on which traditional classification of animals was based?

When division of the zygote reaches the eight-cell stage and the planes of cleavage of the upper four cells line up with those of the bottom four cells so that two tiers of cells result, one directly above the other (like a snowman), the type of cleavage is called 

The number of animal species now known is about