Describe two paths carbon dioxide can take through the carbon cycle.

Explanation:

In the geological cycle, the CO2 that is in the atmosphere, dissolves in rainwater, producing H2CO3 which is an acidic solution. This facilitates the erosion of the silicate rocks by releasing the calcium and HCO3 that are later carried to the oceans where marine organisms assimilate both to build their carbonated shells. When these organisms die, the shells settle and accumulate. This bottom sediment can migrate to an area where pressure and heat partially melt the carbonates. The formation of this magma releases CO2 that escapes into the atmosphere again. It can be combined again with rainwater, completing the cycle.

In the terrestrial environment, the carbon cycle is closely linked to the respiration of living things and plant photosynthesis that removes carbon dioxide from the atmosphere and transforms it into biomass, which feeds herbivorous animals, which will also serve to carnivorous animals. After death, both animals and vegetables suffer the action of decomposers. If the decomposition of this organic matter is total, there is a release of carbonic gas, methane gas, and water, if it is partial, there is a transformation into combustible material (oil and coal). The combustible material, when burned, returns carbon to the atmosphere in the form of CO2. That is, carbon fixed by photosynthesis sooner or later returns to the atmosphere by the decomposition of dead organic matter.

when it is at an intermediate population density

the answer would be   10%