Final answer:
Maya's independent variable for her experiment is the amount of water, and she should alter this to see how it affects plant growth. In an experiment like Gary's, the independent variable being tested is also the amount of water, and controlling variables is crucial to obtain valid results. An experiment without proper controls, like placing one set of plants in the sun and the other in the shade, can lead to inconclusive outcomes. So the correct answer is Option B.
Step-by-step explanation:
In Maya's experiment intended to determine how the amount of water given to a lima bean seed affects how tall it grows, the variable she should change is the amount of water. Variables are important in scientific experiments because they allow us to test how one specific factor influences another. In this case, the amount of water is the independent variable, which is intentionally altered to observe the effect on the dependent variable, which is the plant's growth height.
For Gary's experiment, the variable being tested was the amount of water. The hypothesis he might be testing is that plants given different amounts of water will show varied growth rates. To ensure accurate results, Gary should control other variables such as the type of soil, amount of sunlight, and container size, so these factors do not skew the outcome.
When conducting experiments, it's crucial to have a control group. The control group allows for a comparison to see the impact of the independent variable on the dependent variable. If a student, like the one analyzing detergent's effects on plant growth, does not sufficiently control variables (such as having one group in sun and another in shade), the results of the experiment may be compromised due to multiple changing factors.