Which of the following is not a mechanism for biological evolution?
a. mutation
b. genetic drift
c. inheritance of acquired characteristic
d. natural selection

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.

well, i believe that the answer is 2. : 3

to this answer it would be edge enhancement