There are 4000 units of energy available to grass at the first trophic level of an ecosystem. if the grass is eaten by a mouse and the mouse is eaten by an owl, how many units of energy will be left for the bobcat that eventually eats the owl?

4 units

Explanation:

The 10 per cent law states that only 10 percent of the energy is transferred to another level. The energy from the producers are transferred to different level.

The next successive level will be higher level and getting energy only 10 per cent of the total energy that the prior level has.

If the producers has 4000 units of energy then the primary consumer will have 10% of this energy.

400 units will be available to the primary consumers and secondary consumers will have 10 % of 400= 40 units.

Tertiary consumer will have 10% of 40= 4 units.

hence, the bobcat will have 4 units of energy.

the statement is true