A student performed an investigation to determine if the rate of photosynthesis in elodea, an aquatic plant, is affected by higher than normal concentrations of carbon dioxide gas
in the water in which the plant is growing. After increasing the carbon dioxide
concentration in the water and illuminating the plant with light, which of the following
would be the best indicator of the rate of photosynthesis?

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.