Certify Teacher Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

The correct choice outlines a fundamental principle of ecology known as the 10% rule, which describes how energy is transferred through different trophic levels in an ecosystem. As energy moves from one level to the next, only about 10% of the energy available at one trophic level is passed on to the next. This significant loss occurs due to various factors such as metabolic processes, heat loss, and the energy used for growth and reproduction. Consequently, each higher trophic level has less energy available to support organisms.

In this context, primary producers, which capture energy from the sun, typically utilize a large portion of that energy for their own growth and metabolic functions, leaving only about 10% for primary consumers. This pattern continues up the pyramid, leading to lesser amounts of energy available for secondary consumers and so forth, ultimately resulting in fewer organisms being able to be supported at higher levels of the pyramid.

Understanding this energy transfer is crucial for comprehending ecological dynamics, food web structures, and the efficiency of energy utilization within ecosystems.