We usually think of this as a destructive process as seen here in puerto rico. when over, it is also a constructive process because debris builds up at the base. this is called a a) delta. eliminate b) plateau. c) landslide. d) low lands.

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.

answer; cnidarians;