Biologists are investigating the energetics of rearing mealworms (Tenebrio molitor) as an alternative protein source. Some producers rear mealworms in automated, temperature-controlled vertical intensive facilities, while others use simpler, outdoor open-air shelters.
The table below shows the annual energy inputs and outputs for both rearing systems:
| Energy category (MJ m−2 year−1\text{MJ }\text{m}^{-2}\text{ year}^{-1}MJ m−2 year−1) | Vertical intensive facility | Outdoor open-air shelter |
|---|---|---|
| Input as feed | 28,00028,00028,000 | 12,35012,35012,350 |
| Input as climate control and lighting | 14,00014,00014,000 | 650650650 |
| Output as harvestable insect biomass | 504504504 | 787878 |
Calculate the total energy input for rearing mealworms in the outdoor open-air shelter. Use data from the table.
The total energy input for rearing mealworms in the vertical intensive facility is 42,000 MJ m−2 year−142,000\text{ MJ }\text{m}^{-2}\text{ year}^{-1}42,000 MJ m−2 year−1. Calculate the percentage efficiency of rearing mealworms in this facility.
Use the equation:
percentage efficiency=energy outputtotal energy input×100 \text{percentage efficiency} = \frac{\text{energy output}}{\text{total energy input}} \times 100 percentage efficiency=total energy inputenergy output×10061 exam-style questions on AQA GCSE Biology 7.4 Trophic levels in an ecosystem, covering 7.4.1 Trophic levels, 7.4.2 Pyramids of biomass, and 7.4.3 Transfer of biomass. Each one has a worked solution and a mark scheme showing where the marks go.