What process describes the role of photosynthesis in ecosystems?

The correct answer highlights the fundamental role of photosynthesis in ecosystems, which is the production of glucose using carbon dioxide and water in the presence of sunlight. During this process, plants, algae, and some bacteria convert light energy from the sun into chemical energy stored in glucose. This occurs in the chloroplasts of plant cells where chlorophyll absorbs sunlight.

The process begins when carbon dioxide enters the plant through small openings called stomata, while water is absorbed from the soil through the roots. The energy captured from sunlight drives the chemical reactions that combine these two raw materials to synthesize glucose. This glucose not only provides energy for the plants themselves but also serves as a vital source of energy for herbivores that consume plants, and subsequently for carnivores that consume herbivores. Thus, photosynthesis is crucial for supporting the food chain and maintaining energy flow within ecosystems.

In contrast to this correct choice, the other options focus on different biological processes that do not accurately describe photosynthesis. The conversion of chemical energy into thermal energy pertains to processes like combustion or respiration rather than photosynthesis. The transformation of dead matter into nutrients describes decomposition, which happens after organisms die, while the breakdown of glucose into energy without oxygen refers to anaerobic respiration, which occurs