Which level of consumer has access to the smallest supply of energy?
a. primary
b. secondary
c. tertiary
d. quaternary

Quaternary

Explanation:

Living organisms found in the ecosystem are involved in a feeding chain in order to obtain energy needed for their metabolic processes. This chain is called Food Chain and it consists of steps in which organisms are classified based on their feeding behavior. This step is called TROPHIC LEVEL. The trophic level begins with PRODUCERS up to QUARTENARY CONSUMERS.

As one organism eats another, energy in form of biomass is transferred to such organism. However, only a little fraction of the energy is transferred to the next trophic level as most of the energy (80-90%) is lost as heat during the organism's metabolic activities. Hence, the higher the organism on the TROPHIC LEVEL, the lower the amount of available energy.

Based on this, the QUARTENARY CONSUMER is the highest on the trophic level and will contain the smallest amount of energy available.