Which statement describes how energy flows in ecosystems through photosynthesis and cellular respiration?

• A. Photosynthesis stores energy as glucose; cellular respiration releases energy from glucose; they form a cycle of energy transfer in ecosystems.
• B. Photosynthesis releases energy from glucose and cellular respiration stores energy.
• C. Energy transfer in ecosystems occurs only during decomposition.
• D. Energy is created anew by photosynthesis.

Answer: (A)

Energy flows through ecosystems by transforming solar energy into chemical energy and then using that energy to power life. In photosynthesis, organisms capture light energy and store it as chemical energy in glucose. Later, cellular respiration releases that stored energy from glucose to do work for the cell, converting it into usable ATP and returning byproducts like carbon dioxide and water. Together, these processes link producers and consumers in a continuous cycle of chemical energy transformation, driven by sunlight. The idea that energy is released by photosynthesis or is created anew, or that energy transfer only happens during decomposition, doesn’t fit how energy realmente moves through ecosystems.