Predict: What would happen if precipitation fell onto a fertilized field near a river? How could
that impact the living things that depend on
the river as a water source? (answer in
complete sentences, two sentence minimum)

When there is too much of it in water, it can speed up eutrophication (a reduction in dissolved oxygen in water bodies caused by an increase of mineral and organic nutrients) of rivers and lakes. Soil erosion is a major contributor of phosphorus to streams. Bank erosion occurring during floods can transport a lot of phosphorous from the river banks and adjacent land into a stream, lake, or other water body.

The answer is joseph is observing the colour of the reaction mixture to see whether proteins are present in the given solution.