Which of the following statements about bacteria and archaea is correct?

• A. Bacteria and archaea are multicellular eukaryotes.
• B. Bacteria and archaea are unicellular eukaryotes.
• C. Bacteria and archaea are unicellular prokaryotes.
• D. Bacteria and archaea are multicellular prokaryotes.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the basic classification of organisms based on cell type. Organisms can be broadly classified as prokaryotes or eukaryotes. Prokaryotes lack a nucleus and membrane-bound organelles, while eukaryotes have these features.
2. Step 2: Recall that bacteria and archaea are two distinct domains of life, both consisting of prokaryotic organisms. This means they do not have a nucleus or membrane-bound organelles.
3. Step 3: Recognize that both bacteria and archaea are typically unicellular, meaning they consist of a single cell rather than multiple cells.
4. Step 4: Evaluate the given options by matching these characteristics: bacteria and archaea are unicellular (single-celled) and prokaryotic (lack nucleus), not eukaryotic or multicellular.
5. Step 5: Conclude that the correct statement is: 'Bacteria and archaea are unicellular prokaryotes.'