a control helps to increase the reliability of the results. it allows a scientist to compare it to other group(s) in an experiment. if a scientist notices a significant different btwn the control and the other groups, he can logically conclude that the independent variable has an impact on the dependent variable.
a variable is any factor, trait or condition that can exist in differing amounts or types. there are usually three tpes of variables in experiments: the independent, dependent and contolled. the independent variable variable is the one that is changed by the scientists to figure it's affect on something.
Answer: Herbivore that feeds on producers
An antibiotic ointment could be used for a woman's vagina lips in case of tearing in natural childbirth which can happen if the baby is say a little too large for the opening as long as not too large to require a caesarian.
A, plant with no fertilizer
As the plate gets pushed down it gets closer to the center of the earth so it melts. It is less dense so it rises to the surface, tension builds up, and forms a volcano - I am almost positive this is accurate