When did oxygen levels start to decline from 35 percent down to today's levels? a. before the silurian period b. after the triassic period c. during the permian eriod d. after the carboniferous period

When lactate builds up in a runners muscles it causes a burning sensation what causes this to occur

4. if a cell is placed inside a solution that has a higher concentration of solute than on the inside of the cell, what can be said about the movement of water? a. water will move out of the cell, causing it to shrivel. b. water will move in and out of the cell at the same rate. c. water will move out of the cell, causing it to swell. d. water will move into the cell, causing it to swell.

Where is the nictitating membrane found? a. between the eyelid and the eyeball b. between the retina and the optic nerve c. between the outer and middle ear d. in the organ of corti in the middle ear