The number of trophic levels in an ecosystem are limited. Comment. 

Explanation

The number of trophic level in an ecosystem are each limited and are not more than 4-5. because the amount of energy flow decreases with successive trophic level as only 10% of energy is transferred from one trophic level to the next successive level.
So rest of the energy is lost in the form of respiration and other vital activities to maintain life. if more trophic levels are present, the residual energy will be limited and decreases to such an extent that it cannot further support any trophic level by the flow of energy.
So. the food chain is generally limited to 3-4 trophic levels only.
e.g.,`underset"(30,000J)"("Sun")overset("1 % asborbed")rarrunderset("300J")("Plants")overset("10 % trsnferred")rarrunderset("30J")("Deer")overset("10 % transferred")rarrunderset(3J)"Tiger"`