Albert, a student researcher, varies the amount of food given to rats in an experiment to measure the effect on their learning behavior. In albert's study, the amount of food given is the independent variable.
An independent variable is under the control of the experimenter. Independent variable does not depend on the other variables involved in the experiment. Since the amount of food is varied, it is not depending on other variables like size of mice, weight, etc.
They say how an enzyme perfectly fits into its substrate is alike a "lock and key".
Only one specific enzyme can fit a specific substrate.
<span>The correct answer to this question is a line graph. If Rob needs to create a graph that is able to display the combination of two different values - in this case, level to which the salt has dissolved and time taken - and he needs to have more than one result included, then a line graph is the way to present this.</span>