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

Explanation

### Step-by-Step Solution:

1. **Understanding Trophic Levels**: Trophic levels refer to the different stages in a food chain, where organisms are categorized based on their feeding relationships. Typically, these levels include producers (plants), primary consumers (herbivores), secondary consumers (carnivores), and tertiary consumers (top predators).

2. **Energy Transfer in Ecosystems**: In an ecosystem, energy flows from one trophic level to the next. However, this transfer is not 100% efficient. It is commonly estimated that only about 10% of the energy from one trophic level is passed on to the next level.

3. **Energy Loss at Each Level**: The remaining 90% of energy is lost due to various life processes such as respiration, digestion, and metabolic activities. This significant energy loss limits the amount of energy available to support additional trophic levels.

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