A)
what is the reason for repeating the procedure with distilled
water instead of hydrogen peroxide?
(1 mark)
b)
what is the reason for repeating the procedure with distilled
water instead of liver extract?
(1 mark)

answer; the correct answer is conflict- related aggression; +

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.