A positive control is a group in an experiment that receives a treatment with a known result, and therefore should show a particular change during the experiment. It is used to control for unknown variables during the experiment and to give the scientist something to compare with the test group.
Is the process by which a double-stranded DNA<span> molecule is copied to produce two identical </span>DNA <span>molecules. </span>
C. Mutualism I put the other answer and I got it wrong :(