Question

Most natural food chains are only four or five links long. The number of trophic levels is limited because ______.

Options

• there are more predators than herbivores

• winter kills off most insects and stops the food chains

• the efficiency in utilizing the food eaten at each level is very low

• all of the above

Answer 1

Most natural food chains are only four or five links long. The number of trophic levels is limited because the efficiency in utilizing the food eaten at each level is very low.

Explanation:

At each trophic level, a large amount of energy is lost as heat due to metabolic activities, so only about 10% of energy passes to the next level. Consequently, after a few transfers, the available energy becomes too low to support additional levels, limiting the chain to four or five links.