Organisms that use organic molecules as their source of carbon are called:

• A. Archaea.
• B. Chemoautotrophs.
• C. Heterotrophs.
• D. Autotrophs.

Answer: (C)

Verified step by step guidance

1. Begin by understanding the definitions of the terms provided in the options. This will help you identify the correct classification for organisms based on their carbon source.
2. Archaea are a group of microorganisms that can be found in various environments, but their classification is not based solely on their carbon source. They can be autotrophs or heterotrophs depending on the species.
3. Chemoautotrophs are organisms that obtain energy from chemical reactions and use carbon dioxide as their carbon source. They are not classified as using organic molecules for carbon.
4. Autotrophs are organisms that produce their own food using inorganic substances, typically carbon dioxide, as their carbon source. They do not rely on organic molecules for carbon.
5. Heterotrophs are organisms that obtain their carbon from organic molecules. This classification fits the description given in the problem, as they rely on organic compounds for their carbon source.