Transfer of Energy and Matter · Paper 2 — Free Biology SL Practice Questions

A simplified food web from a lake ecosystem in Sweden is shown below.

A coral reef ecosystem contains the following food web: - Algae $\rightarrow$ Parrotfish $\rightarrow$ Moray eel $\rightarrow$ Reef shark - Algae $\rightarrow$ Zooplankton $\rightarrow$ Damselfish $\rightarrow$ Moray eel $\rightarrow$ Reef shark The moray eel assimilates $800\,\text{kJ}$ from damselfish and $200\,\text{kJ}$ from parrotfish. The reef shark assimilates $15\%$ of the moray eel's total assimilated energy.

A simplified food web for a freshwater lake ecosystem in temperate North America is shown below. Arrows indicate the direction of energy flow. The following data apply to this ecosystem: - Net primary productivity (NPP) of phytoplankton: $20{,}000\,\text{kJ}\,\text{m}^{-2}\,\text{year}^{-1}$ - Respiration rate of phytoplankton: $8{,}000\,\text{kJ}\,\text{m}^{-2}\,\text{year}^{-1}$ - Mean ecological efficiency between each trophic level: $12\%$ - Biomass of Largemouth Bass: $2.5\,\text{kg}\,\text{m}^{-2}$; energy content: $4{,}500\,\text{kJ}\,\text{kg}^{-1}$