Question

using the 10% rule when studying trophic pyramids, if the secondary consumers at the third trophic level obtain 500 joules of energy, how much energy do the primary consumers have at the second trophic level? 500 joules 5,000 joules 50 joules

Explanation:

Step1: Apply the 10% rule formula

The formula is $E_{n - 1}=\frac{E_{n}}{0.1}$, where $E_{n}$ is the energy at trophic level $n$, and $E_{n - 1}$ is the energy at the previous trophic level.

Step2: Substitute the given value

Given $E_{n}=500$ Joules (energy of secondary consumers, trophic level 3). Then $E_{n - 1}=\frac{500}{0.1}$.

Step3: Calculate the result

$\frac{500}{0.1}=5000$ Joules. So the energy of primary consumers (trophic level 2) is 5000 Joules.

Answer:

B. 5,000 Joules