Functioning ecosystems and succession — Question 2

2a)

$\mathrm{E}\mathrm{n}\mathrm{e}\mathrm{r}\mathrm{g}\mathrm{y}\,\mathrm{t}\mathrm{r}\mathrm{a}\mathrm{n}\mathrm{s}\mathrm{f}\mathrm{e}\mathrm{r}\,=\,36/900\,\times \,100\%\,=\,4\%\,\,$

• correctly calculates energy transfer [1 mark]

• shows appropriate working [1 mark]

2b)

At each trophic level, some energy is lost to respiration and decomposition. In these processes, organic compounds that contribute to biomass are converted into inorganic substances, such as CO₂ and H₂O.

• identifies a process that accounts for loss of biomass [1 mark]

• explains the process [1 mark]