Which of the following statements about physical models is not true? a. physical models are often three-dimensional representations. b. physical models are used to represent an object or event. c. physical models are usually in the form of a graph. d. physical models can be used to depict microscopic objects.

ecological efficiency: % of usable energy transferred as

biomass from one trophic level to the next typical is 10% efficient (90% of

energy is lost),is diagramed as the pyramid of energy flow. then osprey eagle

are tertiary consumer and the shrimp are primary consumer, so to balance

mass of shrimp (1/0.1) / 0.1 = 100 kg