posted by jessica .
scientist performed an experiment to determine whether ther is a connection between learning and the ability and food.the group that had been fed had retained this ability but the other had not.the probable reason that the scientist used only mice from the same pure bred stain is so that:
a)generic diffrences would not affect the outcome of the test
b)the experiment would not cost as much
c)the mice would be all the same color
d)the mice would be all the same size
e)the experment could be repeated with the same mice