A farmer grows wheat and uses it to feed cattle. The farmer is considering whether to sell the wheat directly for human consumption instead of feeding it to cattle first. Explain why selling the wheat directly would allow more people to be fed from the same area of farmland.

Energy is lost at each trophic level, so only a small percentage of the energy stored in the wheat is transferred to the cattle.

Cattle use a large part of the energy from the wheat for respiration, movement and maintaining body temperature.

Additional energy is lost in the cattle’s faeces, urine and indigestible material.

Because only about 10 % of the energy from one trophic level is passed to the next, the amount of energy available in the cattle’s meat is far less than the energy that was originally in the wheat.

If the wheat is eaten directly by humans, they are at a lower trophic level; fewer trophic steps mean less energy loss, so more of the original energy can be used to feed more people from the same area of farmland.