Answer:

The mitochondrion is a double membrane-bound organelle found in most eukaryotic organisms. Some cells in some multicellular organisms lack mitochondria. A number of unicellular organisms, such as microsporidia, parabasalids, and diplomonads, have reduced or transformed their mitochondria into other structures.

Answer:

semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells; the site of tissue respiration