The tiger is left with 10J of energy in a grass–deer–tiger food chain. The energy available at grass level is:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) - 1000 J
To explain how much energy was available at the grass level, let's use the 10% rule of energy transfer in trophic levels:
Energy Transfer Efficiency: According to the 10% rule, only about 10% of the energy from one trophic level is transferred to the next. The remaining 90% is lost mainly through metabolic processes and heat.
Energy Calculation: Given that the tiger retains 10J of energy, let's backtrack through the trophic levels to determine the energy available at the grass level.
- Tertiary Consumer (Tiger): 10J
- Secondary Consumer (Deer): Since only 10% of the deer's energy is transferred to the tiger, the deer must have had 10J × 10=100 J
- Primary Consumer (Deer): 100J
- Primary Producer (Grass): Since only 10% of the grass's energy is transferred to the deer, the grass must have had 100J × 10=1000J
Therefore, the energy available at the grass level is 1000J.