Final answer:
A controlled experiment to test whether plants need sunlight to survive would involve comparing the growth of plants exposed to sunlight with plants that are not exposed to sunlight. The independent variable would be the presence or absence of sunlight, and the dependent variable would be plant growth. A control group can be created by using artificial lighting that mimics natural sunlight.
Step-by-step explanation:
A controlled experiment to test whether plants need sunlight to survive would involve comparing the growth of plants exposed to sunlight with plants that are not exposed to sunlight. The independent variable would be the presence or absence of sunlight, with one group of plants placed in a well-lit area and another group placed in a dark room. The dependent variable would be the plant growth, which can be measured by recording the height or number of leaves of the plants over a period of time.
To ensure accurate results, it is important to have a control group. In this experiment, a control group can be created by placing a third group of plants in an area with artificial lighting that mimics natural sunlight. This will allow for comparison and help determine whether any observed differences in plant growth are due to the presence or absence of sunlight.
Other factors that should be controlled include the type of plants used, the type and amount of soil, the amount of water and nutrients provided to each group of plants, and the temperature and humidity conditions. By controlling these variables, the experiment can isolate the effect of sunlight on plant growth.