Answer:
mitochondria
Explanation:
Mitochondria are organelles found in eukaryotic cells that are capable of generating the main part of the energy required for the cellular biochemical reactions. In addition, mitochondria are also involved in distinct biological functions including, among others, cell signaling, death, differentiation and growth. It is believed that mitochondria evolved from prokaryotic organisms which introduced inside others to form eukaryotic cells, this theory is known as the 'endosymbiotic theory'.
