Final answer:
Living organisms contain carbon in their bodies and contribute to the carbon cycle through living processes and upon death. Abiotic reservoirs like the atmosphere and oceans play significant roles in the carbon cycle, especially in photosynthesis.
Step-by-step explanation:
The abiotic carbon reservoirs are indeed the atmosphere and the oceans, where inorganic carbon is dissolved. In addition to these abiotic reservoirs, living organisms incorporate carbon into their bodies, specifically into biomolecules such as carbohydrates, proteins, lipids, and nucleic acids. When these organisms die, the carbon within them contributes to other reservoirs, such as soil, where it is found in dead plants and animals. The biogeochemical carbon cycle ensures the movement and exchange of this carbon between various reservoirs on Earth, which includes the atmosphere, oceans, soil, and the Earth's interior.
The atmosphere is a major reservoir of carbon, mostly in the form of carbon dioxide (CO2), which is essential for the process of photosynthesis. Carbon exchanges between the atmosphere and oceans play a crucial role in regulating the levels of CO2. Autotrophs, such as plants and some bacteria, utilize CO2 along with sunlight to form organic compounds including glucose, which is necessary for their growth and supply energy to other living organisms through the food chain.