Earthworms are primary consumers that can be grown on household food waste such as fruit and salad leftovers. Outline their potential as an energy-containing food source for humans.

State the units used in a pyramid of energy.

a. much loss of energy / 10–20 % loss of energy;

b. low down food chain so efficient;

c. loss of energy through respiration/heat;

d. loss of energy through egestion;

e. less valuable as a food source than primary producers;

f. converts undigestible material into digestible materials;

kJ m^–2 yr^–1 / kilojoules per meter squared per year

Earthworms were recognized as primary consumers, many candidates could state the proportion of energy received and could indicate that the earthworms were using wastes to produce foods. The effects of UV radiation on living tissues were generally well understood.

Earthworms were recognized as primary consumers, many candidates could state the proportion of energy received and could indicate that the earthworms were using wastes to produce foods. The effects of UV radiation on living tissues were generally well understood.