What are the similarities between mitochondria and plastids?

There are various similarities between mitochondria and plastids. Both mitochondria and plastids are double membrane organelles found in eukaryotic cells. Both also are contained with fluid-filled sacs inside the organelles, which assist to maintain a distinct environment inside the organelles. Both also have the porin protein on their outer membranes which helps to increase the layer’s porosity. Additionally, since plasmids and mitochondria have their own DNA for protein synthesis, they are classified as semi-autonomous cell organelles.