A student is observing a sample of pond water and provides the following description in her observations.“I see euglena and paramecium swimming around in the drop of water. A daphnia is feeding on a clump of algae. I see air bubbles around the small clump of algae.”Would you describe what the student saw as a community or an ecosystem? Explain what clue(s) helped you decide.

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.