Final answer:
The question pertains to whether the growth of plants under different conditions is proportional, relating to how factors like sunlight and nutrients affect plant growth. Consistent data reflecting a linear relationship between growth and time or other factors would suggest proportionality. The student's experiment with detergent in the soil has a confounding variable; to properly assess the effect of detergent, the sunlight exposure should be kept constant.
Step-by-step explanation:
The student is asking about the proportionality of plant growth, and whether two different plants exhibit proportional growth given different conditions. To determine if the growth is proportional, we would need consistent data showing that the increase in one variable (such as time or amount of food) results in a consistent increase in another variable (like height or size of the plant). In other words, there should be a constant rate of growth when comparing it to the original height.
An experiment studying plant growth may involve controlled variables such as the amount of sunlight, water, nutrients, and other conditions essential for plant development. Proportional growth would mean that as one plant grows, another plant would grow at a consistent rate relative to the first, typically described by a linear relationship. This concept is essential in understanding how different factors, like sunlight in Gary's observation, affect plant growth.
For the case of the student using detergent in soil, it's important to note that the presence of detergent and the amount of sunlight are two independent variables that affect plant growth; he should alter only one variable while keeping the other conditions constant to isolate the effects. Additionally, the comparison between plants in different lighting conditions, like those under blue, green, and orange lights, would help predict which light is most beneficial for photosynthesis based on the properties of chlorophyll a and b.