Amount of energy available to secondary consumers

Subject : Biology

Question:

In a given ecosystem, producers convert solar energy into 15,000 kcal of chemical energy stored in organic compounds. Which of the following is the most likely amount of energy available to secondary consumers?

A: 1.5 kcal

B: 150 kcal

C: 1,500 kcal

D: 13,500 kcal

Expert Verified Solution:

Correct Answer: B: 150 kcal

In an ecosystem, energy transfer between trophic levels follows a pattern known as the energy pyramid. Typically, only about 10% of the energy from one trophic level is passed on to the next. This is due to energy losses at each level, mainly through metabolic processes and heat.

Given that producers convert solar energy into 15,000 kcal of chemical energy, this energy is available to primary consumers (herbivores). According to the 10% rule:

Primary consumers would receive approximately 10% of the producer energy:
15,000 kcal × 0.10 = 1,500 kcal

Secondary consumers would then receive about 10% of the energy available to primary consumers:
1,500 kcal × 0.10 = 150 kcal

Thus, the most likely amount of energy available to secondary consumers is 150 kcal.