Willa tests her model by placing the large clay ball, a single marble, and a single ball bearing one at at time on the plastic. Which object creates the deepest well? How can these observations be applied to solar system objects? Explain.

one centimetre is equal to 0.01 metres

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.