Answer: Really hope this helps you.
Explanation: it depends in what you are using it for if you are using it for math then it means a relation from a set of inputs to a set of possible outputs where the input and the output is related exactly.
I think two are stem cell research and cloning
I think the correct answer would be C. It would be restricting water and/or nutrients, instead of supplying ample quantities of both that would not change the results of the experiment. This is because you are still supplying the same amount of nutrients and other things needed by the plant so the ratio of the growth of the plants will still be the same.
An onion is a plant so it would have a cell wall, but a human cell is an animal cell so it doesn't have a cell wall. I'm not sure if that's the type of answer you're looking for though.
