Question

Assuming a 90% loss of energy across each trophic level, state how much energy would remain at the fourth trophic level if photosynthesis makes available 100 000 KJ of potential energy to the consumers. Show your reasoning/calculations. Construct a properly labeled pyramid to represent this.

Answer 1

If there is a 90% loss of energy across each trophic level, then only 10% of the energy is available to the next level. Therefore, the amount of energy available to the fourth trophic level is:

100 000 KJ x 0.1 x 0.1 x 0.1 = 100 KJ

Only 100 KJ of energy would remain at the fourth trophic level.

Here is a properly labeled pyramid to represent this:

```

Fourth Trophic Level (Carnivores) 100 KJ

Third Trophic Level (Secondary Consumers) 1 000 KJ

Second Trophic Level (Primary Consumers) 10 000 KJ

First Trophic Level (Producers) 100 000 KJ

```

Note that the fourth trophic level is at the top of the pyramid, followed by the third, second, and first trophic levels. Each level represents a different group of organisms, with producers at the bottom and carnivores at the top. The amount of energy available decreases as you move up the pyramid, reflecting the loss of energy at each trophic level.