Final answer:
To determine the relationship between sunlight and plant growth, a controlled experiment must be accurately designed. Gary's hypothesis suggests sunlight influences growth, and by keeping the container size and watering consistent, he ensures other variables do not interfere. A well-structured experiment design requires changing only the light intensity and measuring the corresponding plant growth or photosynthesis efficiency.
Step-by-step explanation:
Exploring Plant Growth in Response to Sunlight
To understand the relationship between sunlight and plant growth, a controlled experiment must be set up correctly. For instance, in Gary's hypothesis regarding plant growth, option b, 'Plants that get more sunshine grow larger than plants that get less sunshine,' is a reasonable statement, as it directly addresses the observed phenomenon and sets up a measurable outcome.
The scientific reason Gary might want all plants to have the same size containers, as indicated in option b, is to 'make sure the size of the container did not affect differential plant growth' to ensure any observed differences in plant growth are due to sunlight exposure only and not container size. Similarly, ensuring all plants receive the same amount of water, as per option a, is to test the exclusive effect of sunlight on plant growth, thus eliminating water as a variable.
Regarding the experiment design to determine the relationship between light intensity and efficiency, it is essential to provide a detailed procedure with a variable that changes, which in this case is the intensity of the light, and to measure how it affects the plants' growth or photosynthetic efficiency. Plant growth or photosynthesis can be measured quantitatively, such as through growth rate, biomass accumulation, or oxygen production, to reliably ascertain the effect of light intensity.