Answer:
The correct answer is "chloroplasts and mitochondria".
Explanation:
Chloroplasts and mitochondria are two essential organelles because of its function of producing Adenosine triphosphate (ATP), the "molecular unit of currency". Chloroplasts are organelles that are found in plants and work in light conditions, whereas mitochondria could produce ATP in the dark. Since the biologist found that the heavier fraction could produce ATP in light it is very likely that it will have chloroplasts, while the light fraction that produces ATP in the dark would likely have mitochondria.