They are not found in plant cells. And one other thing, one other organelle that plant cells have and animal cells do not have is the chloroplast. The chloroplast is basically the organelle that uses oxygen and some type of carbon source. So CO2 and oxygen or actually, no, it uses CO2 and water to create sugar molecules and it releases oxygen into the atmosphere. That's the oxygen that we basically breathe in. So we can imagine that if our mitochondria is the nuclear power plant, the chloroplast is our solar power plant.