I can’t give you a specific answer because I’m not sure what your lab is. However, an independent variable is the variable that is changed, the dependent variable is the variable that is affected by the change, and the constant variables are those which remain the same throughout the entire experiment.
The organisms in a pond and the physical factors <span>influencing them best describe "an ecosystem" since this is a self-contained environment will multiple organisms. </span>
To have similar shape or function, although not derived from similar lineage.
