Final answer:
Microorganisms can completely degrade chlorinated organics to carbon dioxide, but not petroleum or uranium.
Step-by-step explanation:
Microorganisms are capable of completely degrading chlorinated organics to carbon dioxide. Chlorinated organics are compounds that contain chlorine atoms, such as certain pesticides and solvents. Microbes have enzymes that can break down these compounds into simpler forms, including carbon dioxide. On the other hand, petroleum and uranium cannot be completely degraded to carbon dioxide by microorganisms. While microorganisms can break down some components of petroleum, such as hydrocarbons, they may not be able to fully convert them to carbon dioxide. Similarly, microorganisms do not play a significant role in the degradation of uranium.