Oxygen is a small molecule and it's nonpolar, so it easily passes through a cell membrane. Carbon dioxide, the byproduct of cell respiration, is small enough to readily diffuse out of a cell. Small uncharged lipid molecules can pass through the lipid innards of the membrane.
TB. It is open to change.he thing about science is that a discovery may be made today and written up but by tomorrow something else is found that edifies what was found or proves it incorrect or make it obsolete. .Therefore the answer is <span>B. It is open to change</span>
D. Thigmotropism. A "tropism" is a plant movement in response to an environmental stimulus, and "tropo" means "touch." Plant cells change their movements when they detect a change in pressure after having contacted something. It is not A because germination is the sprouting of seedlings. It is not B because photosynthesis is the action of plants to convert light energy into chemical energy. It is not C because phototropism refers to movement in response to a change in light ("photo" means "light").
