Question

Question 23
Oxygen liberated during photosynthesis comes from

(a) water
(b) chlorophyll
(c) carbon dioxide
(d) glucose

Answer 1

(a) water

Photosynthesis is the process used by plants, algae and certain bacteria to harness energy from sunlight into chemical energy.

There are two types of photosynthetic processes: oxygenic photosynthesis and anoxygenic photosynthesis.
Oxygenic photosynthesis is the most common and is seen in plants, algae and cyanobacteria. During oxygenic photosynthesis, light energy transfers electrons from water to carbon dioxide, which produces carbohydrates. In this transfer, the $C{O}_2$ is "reduced," or receives electrons and the water becomes "oxidised," or loses electrons. Ultimately, oxygen is produced.