* Stomata: These are specialized structures found on the surface of leaves and stems of plants. They are not cells themselves, but rather pores surrounded by two guard cells. Stomata regulate gas exchange (taking in carbon dioxide and releasing oxygen) and water loss.

* Mitochondria: These are organelles found in all eukaryotic cells, including plants, animals, fungi, and protists. They are responsible for cellular respiration, the process of converting food into energy.

In summary:

* Stomata are structures found only in plants, but not individual cells.

* Mitochondria are organelles found in all eukaryotic cells, including plants.