Atmospheric oxygen gas is a pure substance

Substances that can pass through cell membranes by diffusion include a. na ions. b. proteins c. glucose. d. oxygen.

When the solution concentration on the outside of a cell is greater than thesolution concentrate on the inside of the cell, what type of solution is the cellwithin?

Which part of the spine is likely to cause a nerve signal to travel faster? a. backbones b. white matter c. nuclei d. gray matter