Explanation:
because it allows you to eliminate or isolate variable/ it allows the experiment to minimize the changes in all the variables except the one being test.
I'm not gonna choose bc I'm not 100% sure either so read what's above, think it over and choose wisely
hope I helped a little and good luck :)
Answer:
im pretty sure it is underpopulation.
The ratio of the outcomes in that Punnett Square is 2:2