Astudent conducts an experiment to determine how the amount of water given to a plant affects its growth.
which of the following is not a control for this experiment?
a. the type of plant
b. the amount of soil
c. the amount of water
d. the amount of time in the sun

The answer is c. the amount of water.

A control of the experiment is an element that is not changed during the experiment. Not changing it allows comparison with the variables that are being tested.
So a student will use several plants of the same type, put it in the same amount of soil and leave it in the sun for the same amount of time. These are control elements. He will change only the amount of water to determine how different amounts of water will affect a plant growth. All these suggest that in this experiment, the amount of water is not a control.

The answer is C. the amount of water.

In every experiment, you must determine a set of controls to maximize its accuracy and reliability. Controls are the ones that are kept constant in a series of trials during an experiment. So if you want to determine the how the amount of water (independent variable) given to a plant affects its growth (dependent variable), you must not make the amount of water a control in the experiment.

If you get a map and put the countries a states all together it forms all one piece you can also tell because of the earth quakes

Atp is is our little "pocket" of energy. of course, if you have too little, then it means you have too little energy, and you'll pass out. the way to not have enough, is to have no energy sources (glucose, fats, proteins). you can't have too many atp molecules. cycles like the krebs cycle produce it, but if you have too much of any substrate (or too little for that matter), the cycle stops and atp is no longer made (it stops until substrate levels are such that the process can go on). in any case, this is unlikely since atp is constantly hydrolyzed and remade, even while you're asleep. you won't have too much. if you have zero, you are dead or dying.