Final answer:
Volutin granules are the type of inclusion containing polymerized inorganic phosphate. They are found in prokaryotic cells and store excess phosphate. They can be observed as dark-staining granules under a light microscope.
Step-by-step explanation:
The type of inclusion containing polymerized inorganic phosphate is called volutin granules. Volutin granules are found in prokaryotic cells and they store excess phosphate in the form of polyphosphate. They appear as dark-staining granules when viewed under a light microscope.