Q1a. A company is growing algae in big tanks to make fish food. However, the algae are not growing very quickly, and they suspect either phosphorus, nitrogen, or iron is limiting. What could the company do to figure out which nutrient is limiting?
* Add phosphorus to one tank, nitrogen to another, and iron to a third, and see which treatment increases algal growth.
* Add phosphorus, iron, and nitrogen to all tanks, and see which nutrient increases algal growth.
* Add phosphorus to all tanks because phosphorus is the nutrient that limits algal growth.
* Add nitrogen to all tanks because nitrogen is the nutrient that limits algal growth.
Q1b. Which of the following statements about eutrophication is TRUE?
* Eutrophic bodies of water are characterized by murky water with large phytoplankton blooms.
* Climate change will not affect eutrophication because phytoplankton growth is unrelated to temperature.
* Eutrophication is typically driven by natural processes like rock weathering and nitrogen fixation.
* Eutrophication can harm fish and other aquatic species but does not cause health problems for humans.
Q1c. How can an increase in algal population size kill fish?
* Algae clogs the gills of the fish, preventing them from breathing.
* Algae clogs the mouths of the fish, preventing them from eating.
* The algae use up the oxygen in the water as they photosynthesize.
* When the algae die, their decomposers use up the oxygen in the water.