Mitochondria are the cell organelles present in the eukaryotic cells (plant and animal cells). These are oval or oblong in shape and are surrounded by double layered membrane.
The inner membrane of mitochondria folds inside and forms the structures called cristae. This leads to the increase of the internal surface area in mitochondria.
The mitochondria structurally resembles like plastids, which are present in some eukaryotic cells such as plant cells but not in animal cells. Unlike Mitochondria, plastids helps in the photosynthesis and contains pigments. While, mitochondria helps in the formation of ATP and helps in other cellular processes.