Many biological processes are cyclical. Examples of cycles can be found at the level of the cell, the organism and the ecosystem.
Describe processes in the carbon cycle that produce or use carbon dioxide.
photosynthesis uses carbon dioxide / reduces carbon dioxide concentration of the atmosphere;
autotrophs/plants/cyanobacteria convert/fix carbon dioxide into carbon/organic compounds;
cell respiration produces/releases carbon dioxide;
glucose/carbon/organic compounds oxidised/broken down to produce/release carbon dioxide;
carbon dioxide released from aerobic (cell) respiration AND anaerobic respiration in yeast/plants (but not animals);
carbon dioxide released from saprotrophs/detritivores/decomposers from dead organic matter / during decay/decomposition/respiration;
(partially) decomposed organic matter can lead to the formation of peat / fossilized organic matter (coal/oil/natural gas)
carbon dioxide released when carbon/organic compounds burn / during combustion (of biomass/fossil fuels) / forest fires;
carbon dioxide dissolves in aquatic ecosystems / can form carbonic acid/hydrogen carbonate ions;
reef-building corals/molluscs use calcium carbonate to make/build shells/exoskeletons or other body parts;
hard parts/shells/exoskeletons / precipitation of calcium carbonate to form limestone/tufa;