SAT Subject Biology Practice Question 147: Answer and Explanation
17. Ecologists measured the evapotranspiration and net primary production of different ecosystem types. Their results are shown in the graph.
The graph shows net primary production. Based on the data, which biome could potentially have a gross primary production rate equivalent to 500 grams per square meter per year?
A. Tropical rain forest
B. Temperate forest
C. Alpine forest
Correct Answer: D
Compared to net primary production, gross primary production is higher, because it includes energy used (and lost) in cellular respiration. Tundra, with a net primary production of approximately 250 g/m2/year, could potentially have a gross primary production of 500 g/m2/year.