Question

If the energy produced by plants is 800,000 kJ, then how much energy will exist at the level of secondary consumers?

• A. 80 kJ
• B. 800 kJ
• C. 8,000 kJ
• D. 80,000 kJ
• E. 800,000 kJ

Answer 1

The correct option is C 8,000 kJ

According to the 10 percent law, when energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed on. The remaining is lost during transfer, broken down in respiration, or lost to incomplete digestion by higher trophic levels.

As per this rule, if the plant produces 800,000kJ of energy then only 10% of this is passed to the next trophic level which is the primary consumers. So, the energy obtained by the primary consumer will be 80,000kJ.

Now, only 10% of this 80,000kJ is passed on to the next trophic level (secondary consumers) which is 8,000KJ.

So, the correct answer is option C.