Which of the following groups is composed entirely of unicellular organisms?

• A. Bacteria
• B. Animals
• C. Fungi
• D. Algae

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definition of unicellular organisms — these are organisms made up of a single cell that performs all life functions independently.
2. Step 2: Review each group listed: Bacteria, Animals, Fungi, and Algae, and identify whether their members are unicellular or multicellular.
3. Step 3: Recognize that Bacteria are prokaryotic microorganisms and are exclusively unicellular.
4. Step 4: Note that Animals are multicellular organisms composed of many specialized cells.
5. Step 5: Understand that Fungi and Algae can be either unicellular or multicellular, but neither group is composed entirely of unicellular organisms.