Mention the similarities and differences between mitochondria and plastid.

Hint: The endosymbiotic theory, which holds that eukaryotic mitochondria and plastids arose from the engulfment and integration of a bacterium by another cell, has long been a source of contention, but increasing evidence has led to the theory's substantiation and universal acceptance.

Complete answer:
Mitochondria are the cell's powerhouse. It is an organelle that is in charge of ATP production in the cell. This ATP serves as the cell's "currency" and is primarily used for aerobic respiration.
Plastids, like mitochondria, assist in the production and storage of food (glucose). They can only be found in plants and contain various pigments.
Mitochondria and plasmids are organelles with two membranes.
Similarities:
1. Porin protein is found in the outer membranes of mitochondria and plastids, making the outer layer more permeable.
2. Mitochondria and plastids have their DNA for protein synthesis, so they are classified as semi-autonomous cell organelles.
Difference between Mitochondria and Plastids

Due to the organelles being surrounded by a double membrane and the integrity of the separate mitochondrial compartments must be maintained, division (fission) and fusion of these organelles are topologically complex processes.

Note:
It is widely assumed that mitochondria and plastids evolved from bacteria engulfed by nucleated ancestral cells. Both types of organelles have their genomes, as well as their biosynthetic machinery for producing RNA and organelle proteins, as a relic of this evolutionary past.