A porcupine eats 3,000 J of plant material. Of this, 2,100 J is indigestible and is eliminated as feces, 800 J are used in cellular respiration, and 100 J are used for growth and reproduction. What is the approximate production efficiency of this animal?

Question

Quizplus · Accepted Answer

Production efficiency is calculated as the energy used for growth and reproduction divided by the total energy consumed, excluding indigestible energy. Here, it is 100 J / (3,000 J - 2,100 J) = 100 J / 900 J = 0.111 or 11.1%, which is closest to 3%.

A Porcupine Eats 3,000 J of Plant Material