Surface Area to Volume Ratio
The larger the organism the smaller the surface area to volume ratio e.g. polar bear. this is one advantage because they loose less heat.
In hot climates large animals like elephants are adapted to the heat because they have large ears which increase the surface area and dont increase the volume significantly as they are so thin. This helps them loose heat.
The carbon cycle basically shows how carbon is recycled. Plants take in CO2 for ohotosynthesis. They then release some of that CO2 back in the atmosphere when they respire. When animals eat the plant, some of the carbon in the plant is transferred. Again, some of it is transferred as CO2 back into the atmosphere when respiration takes place. When living organisms die, they are decayed by decomposers. When decomposers respire, they give out CO2.
Carbon is recycled through 1) photosynthesis 2) feeding 3) respiration 4) sedimentation ( fossil fuels formed here ). 5) combustion 6) decay 7) natural disasters eg. Volcanoes release CO2.