Plants produce oxygen in photosynthesis. Where does the oxygen come from?

Question

a. the sun
b. chlorophyll
c. glucose
d. water
e. a turn of the Calvin / Benson cycle

Answer 1

d. water.

Answer 2

D. Plants split water molecules using energy in the light-dependent reactions. They keep the H+ and associated electron to use and discard the oxygen.

A. The sun gives light which is the energy that drives photosynthesis and splits the water, but it's not the source of the oxygen.
B. Chlorophyll absorbs the light energy and passes an electron down the electron transport chain, producing the energy to split water, but it's not the source of the oxygen either.
C. Glucose is the end product of photosynthesis.
E. The Calvin cycle builds glucose. Water has already been split and oxygen released in the preceding light-dependent reactions.

Answer 3

Technically, the Oxygen comes from the CO2 that is absorbed by the Chlorophyll in the plant. The sun's rays stimulate the chloroplasts in the plant cells and cause photosynthesis, absorbing CO2 from the atmosphere, processing the Carbon for food, and releasing the O2 back into the atmosphere.

A brilliant natural process, I must say. NASA is considering it as a way of replenishing the O2 supply onboard the ship that will take a crew to Mars someday.

Answer 4

d. the water splits in photosystem 2. Since water is H2O, they hydrogens get split from the oxygens

Answer 5

From carbon dioxide, so f) none of the above

Answer 6

the whole process. go read a biology book

Answer 7

CO2. simple.

Answer 8

e ?