Answer: Cell.
- A Atom
- B Molecule
- C Cell
- D Tissue
Correct answer: C. Cell
Explanation: The cell is the basic structural and functional unit of all living organisms (Cell Theory).
Animal cell structure with major organelles labeled. Image: LadyofHats (Mariana Ruiz), Public Domain, via Wikimedia Commons.
Concept context
Cell theory, prokaryotic vs eukaryotic cells, organelles and their functions. Foundation of all biology.