AICE Marine Science Paper 2 Practice Exam

The answer indicating that typically 10% of energy is transferred to the next trophic level reflects the concept known as the "10% rule" in ecology. This principle suggests that when energy is passed from one level of a food chain to the next, only a fraction of the energy (about 10%) is converted into biomass, while the majority is lost as heat, metabolic processes, and through other forms of energy transfer, such as respiration or waste.

This rule generally applies across various ecosystems, although the exact percentage can vary depending on specific environmental conditions and the organisms involved. The energy loss at each trophic level underscores why ecosystems usually have fewer organisms at higher trophic levels; there simply isn’t enough energy available to support a large biomass of predators compared to their prey.

The other percentages given do not align with this established ecological rule. For example, a 5% transfer rate would suggest less efficiency than is commonly observed, whereas rates of 15% or 20% would indicate a more productive system than is typical, which is often not sustainable in most natural environments. Understanding this energy transfer is crucial for grasping ecological pyramids and the dynamics of food chains.