Question

The model above shows how carbon is cycled through an ecosystem. In your Science Notebook, identify the four spheres through which carbon cycles, and then make a listing of how living things are related to the cycling of carbon. Be sure to consider both the things you can see and the things you cannot.

What is the relationship between cellular respiration and photosynthesis in terms of carbon cycling?
What are the impacts of human-derived carbon sources on the cycling of carbon?
Why would a scientist (or student) use models of the carbon cycle (or other phenomena) instead of the real things?
make it short and don't put it in points

Answer 1

The four spheres through which carbon cycles are the atmosphere, biosphere, hydrosphere, and geosphere. Living things participate by converting carbon between forms: plants, algae, and phytoplankton take up atmospheric or dissolved CO2 by photosynthesis and build organic matter; animals and microbes eat that biomass and move carbon through food webs; all organisms release CO2 back to air or water through cellular respiration; decomposers and microbes break down dead material, returning CO2 or methane; some organic carbon is buried and, over long time, becomes fossil fuels; microscopic life and dissolved inorganic carbon in oceans are major, often unseen, players in these exchanges.

Photosynthesis and cellular respiration are complementary parts of the carbon cycle: photosynthesis removes CO2 and stores carbon in organic molecules, while respiration breaks those molecules down and returns CO2 to the atmosphere or water, keeping carbon moving through the system.

Human-derived carbon sources—mainly burning fossil fuels, cement production, and deforestation—add large amounts of CO2 and methane faster than natural sinks can absorb, raising atmospheric CO2, driving climate change, and causing ocean acidification while disrupting long-term carbon storage.

Scientists and students use models because real ecosystems are too large, slow, complex, or risky to manipulate directly; models simplify and isolate key processes, let you run experiments and future scenarios quickly and safely, and help visualize and quantify how the carbon cycle responds to changes.