Step 1: Click touch here to begin the app. You want to move to the "Choose Your Challenge!" menu. From the menu choose “Build a Membrane!" Dr. Vial has a vile weapon

(note the play on words) that destroys plasma membranes. Without the plasma

membrane

all

cells of living things will die because they are unable to

maintain

homeostasis

Paleontologists have found plant fossils deep within the layers of the north polar region. these leaf fossils have been labeled as to the rock layers they were found in, with the lower numbers being layers close to the earth's surface and higher numbers representing deeper layers. according to the numbers of these four leaf fossils, what might you infer?