Victory for the ACT Student Text 15e

S CIENCE Q UIZZES • 331

1. According to the diagram, the trophic level with the largest relative biomass is the: A. 4° consumers. B. 3° and 2° consumers. C. 1° consumers. D. producers. 2. From the information in the diagram, one can conclude that at any given time: F. 10 seals may be found for every mackerel. G. the relative dry weight of all carnivores combined is far greater than that of the herbivores alone. H. only 1 percent of all producers live long enough to be eaten by a mackerel. J. the relative dry weight of every consumer trophic level is less than that of the trophic level on which they feed. 3. Organisms from which trophic level are most likely to be found near the water surface where light can penetrate? A. 4° consumers B. 2° consumers C. 3° consumers D. producers 4. If there were an additional trophic level of carnivores (5° consumers), its relative biomass at any given time would be approximately: F. 0.1 kg. G. 1 kg. H. 9 kg. J. 1,000,000 kg.

EXPLANATIONS

1. (D) Science/Interpretation of Data/ Com- prehension The trophic level with the largest biomass is at the base of the pyramid: producers (100,000 kg). 2. (J) Science/Evaluation of Models/Analysis The relative dry weight of the organisms in each trophic level decreases from bot- tom to top. That is, the relative weight of each level’s organisms is smaller than the relative weight of the food it eats in the next lower level. 3. (D) Science/Evaluation of Models/Analysis Light is always needed by the photosyn- thetic organisms of any ecosystem. Since light does not penetrate into the deeper waters, producers must remain near the water surface. 4. (F) 6FLHQFH 6FLHQWLÀF ,QYHVWLJDWLRQ $SSOL- cation Each trophic level supports 10% of the biomass found in the previous trophic lev- el. Therefore, since the 4° consumer tro- phic level has a relative biomass totaling 10 kg, it will support 1 of 10 kg kg 10 1 of relative biomass in the next trophic level.