What are Constant/control variables

constant = changes and control is used as the basis of comparison

Explanation:

Constant variables are variables that do not change

e.g such as the temperature ( if it's meant to be kept at a constant temp).

Control variables are meant to be kept constant to allow for a comparison and thus determine the effect of IV (independant variable) and DV ( dependant variable)

c

explanation:

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.