Answer:
No! ( in my opinion)
Step-by-step explanation:
Okay! just because they were not in all the animal and plant cells does not mean their in the cheek and onion cells. I did this experiment in class. we actually were able to find some of the the mito in the onion. All animals and plants are different in some kind. some are rare some are not, this planet contains over a hundred animals and plants we dont know about. hope this helps.