Why are there seldom food chains with more than four trophic levels in an ecosystem?

• A. Because producers cannot supply enough oxygen for more than four levels.
• B. Because decomposers outcompete consumers at higher trophic levels.
• C. Because energy is lost at each trophic level, leaving insufficient energy to support additional levels.
• D. Because higher trophic levels reproduce more quickly, limiting the number of levels.

Answer: (C)

Verified step by step guidance

1. Understand the concept of trophic levels: Trophic levels represent the hierarchical positions in a food chain, starting with producers (plants and algae) at the base, followed by primary consumers (herbivores), secondary consumers (carnivores or omnivores), and so on.
2. Learn about energy transfer in ecosystems: Energy is transferred from one trophic level to the next, but only a small fraction (approximately 10%) of the energy is passed on. The rest is lost as heat, metabolic processes, or waste.
3. Recognize the implications of energy loss: Due to the significant energy loss at each trophic level, there is progressively less energy available to support organisms at higher levels. This limits the number of trophic levels an ecosystem can sustain.
4. Understand why ecosystems seldom have more than four trophic levels: The energy available at the fourth trophic level is often insufficient to support a fifth level, as the energy diminishes drastically with each transfer.
5. Connect this concept to the correct answer: The correct answer is that energy is lost at each trophic level, leaving insufficient energy to support additional levels. This principle explains why food chains are typically limited to four trophic levels.