Question

Imagine you have a five-step food chain. If 100 percent of the energy is available at the first tropic level, what percentage of the energy is available at the highest trophic level?

Answer 1

In a five-step food chain, only about 0.01 percent of the energy available at the first trophic level is available at the highest trophic level due to the loss of energy at each step, primarily as heat and through metabolic processes.

Step-by-step explanation:

When considering a five-step food chain and the transfer of energy from one trophic level to the next, it's important to understand that only about 10 percent of the energy is transferred up to each subsequent level. Starting with 100 percent of the energy at the first level, we can calculate the percentage of energy available at the highest trophic level by sequentially applying the 10 percent rule. To do this, we repeatedly take 10 percent of the remaining energy from one level to the next.

• First to second trophic level: 10% of 100% = 10%.
• Second to third trophic level: 10% of 10% = 1%.
• Third to fourth trophic level: 10% of 1% = 0.1%.
• Fourth to fifth trophic level: 10% of 0.1% = 0.01%.

Therefore, at the fifth and highest trophic level in this chain, only 0.01 percent of the original energy is available. The rest of the energy has been used by organisms for metabolic processes or lost to the environment as heat.