Carbon is present in both the hydrosphere and the atmosphere as carbon dioxide (CO2). This compound is derived from the combustion of plant remains and the respiration of plants and animals. CO2 is absorbed by chlorophyllated plants and chemosynthesizing bacteria and is used to form carbonated organic compounds (cellulose and starch).
Part of this gas returns directly to the atmosphere by breathing in the plant. The plants are ingested by the animals. From the combustion of these foods in the animals' organism, CO2 returns to the atmosphere, or when these animals die, it will be part of the organic debris that, due to the death of chlorophyllated vegetables and bacteria, will form vegetable debris, which upon combustion will return the CO2 to the atmosphere.
The Amoeba is an asexual reproducer, which means it reproduces on its own. The bird is a sexual reproducer, which means it has to have a mate, which helps to diversify the DNA.
