Certify Teacher Science Practice Exam 2025 - Free Practice Questions and Study Guide for Science Certification

The cycling of matter in ecosystems is best explained by biogeochemical cycles. These cycles encompass the movement of essential elements and compounds, such as carbon, nitrogen, oxygen, and water, through various components of the ecosystem, including the atmosphere, lithosphere, hydrosphere, and biosphere. In these cycles, matter is transformed and reused, allowing nutrients to be recycled and made available to living organisms over time. For example, the carbon cycle illustrates how carbon dioxide is absorbed by plants during photosynthesis and then transferred through various trophic levels as animals consume the plants and eventually decompose, returning carbon to the soil and atmosphere.

In contrast, while the law of conservation of energy discusses how energy is neither created nor destroyed but rather transformed, it does not specifically deal with the cycling of matter itself. Food chain dynamics describe the flow of energy through different organisms in an ecosystem but do not capture the broader concept of nutrient recycling. Ecological succession refers to the gradual process of change in species composition and structure of an ecological community over time, which is distinct from the systematic cycling of matter. Thus, biogeochemical cycles are fundamental to understanding how matter moves and is transformed within ecosystems.