Cyanobacteria are a group of photosynthetic bacteria. These bacteria use sunlight as their energy source and carbon dioxide as their carbon source. Cyanobacteria are ________________.

• A. Chemoautotrophs.
• B. Photoautotrophs.
• C. Chemoheterotrophs.
• D. Photoheterotrophs.

Answer: (B)

Verified step by step guidance

1. Understand the definitions of the terms: Photoautotrophs, Chemoautotrophs, Chemoheterotrophs, and Photoheterotrophs.
2. Photoautotrophs are organisms that use sunlight as their energy source and carbon dioxide as their carbon source.
3. Chemoautotrophs obtain energy from chemical reactions and use carbon dioxide as their carbon source.
4. Chemoheterotrophs obtain both energy and carbon from organic compounds.
5. Photoheterotrophs use sunlight for energy but obtain carbon from organic compounds.