Figure 53.4 -After Looking at the Experiment in the Figure Above, What

Multiple Choice

Figure 53.4
-After looking at the experiment in the figure above, what can be said about productivity in marine ecosystems?

A) Marine organisms break down iron for energy and thus for productivity.
B) Nothing can be said based on this information.
C) Productivity increases when chlorophyll a is added.
D) Iron can be a limiting nutrient in productivity.