O2 (oxygen) is not needed for photosynthesis to occur.
Here is a Answer to your question:
Mitochondria
Mitochondria are membrane-bound cell organelles (mitochondrion, singular) that generate most of the chemical energy needed to power the cell's biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP).
I am sorry if this was not helpful
Hope this was helpful
C)Fossil Aging, I think...
....Hope it helps, have a good rest of the day:)
Answer:
Its number 4 , After billions of years, cyanobacteria turns into iron; the iron beds are remnants from cyanobacteria. its 7th grade science.
Explanation: