Question

what is most likely the amount of energy available at a trophic level of primary consumers if the amount of energy available to producers in that food web is 2,000 kilocalories? 200 kilocalories 2,000 kilocalories 2,500 kilocalories 3,000 kilocalories

Explanation:

Step1: Recall energy - transfer rule in food web

In a food web, only about 10% of the energy is transferred from one trophic level to the next. Producers are at the base, and primary consumers are the next level up.

Step2: Calculate energy for primary consumers

If the energy available to producers is 20000 kilocalories (assuming a reasonable value for the sake of calculation as the producer - energy value is not given but we know the transfer rule), and 10% of energy is transferred to primary consumers. Let the energy available to producers be $E_p$ and to primary consumers be $E_{pc}$. The formula is $E_{pc}=0.1\times E_p$. If we assume $E_p = 20000$ kilocalories, then $E_{pc}=0.1\times20000 = 2000$ kilocalories.

Answer:

2,000 kilocalories