Final answer:
The control in the corn row experiment is the row that did not receive fertilizer, used to measure the effect of the fertilizer on the growth. Gary's hypothesis is that sunlight affects plant growth, and he uses consistent pot size and water amounts as controls in his experiment.
Step-by-step explanation:
In the context of scientific experimentation, the control is the part of the experiment that does not change and is used as a benchmark to measure the effects of the variable being tested. In the first scenario mentioned, the control would be row 2 of the corn - the row that did not receive any fertilizer. This allows the scientist to observe the effects of fertilizer by comparing the growth of corn in row 1 (which received fertilizer) against the growth of corn in row 2 (which did not).
For Gary's experiment, he is clearly aiming to test the effect of sunlight on plant growth. The consistency in pot size, type, and the amount of water each plant receives are all controls meant to ensure that these factors do not influence the outcome of the experiment. Therefore, the answer to question 1 is 'b', question 2 is 'b', and question 3 is 'a'.
In this question, the student needs to determine which brand of fertilizer Cala would need more of to fertilize her vegetables. The directions for Grow Better fertilizer state that a 25-pound bag covers a 1,000-foot row of vegetables. Therefore, Cala would need more of the fertilizer from the brand that covers less area with the same amount of fertilizer. Since both brands are not specified, it is not possible to determine which brand Cala would need more of based on the information provided. It is not possible to determine from the information provided.