What is the unique process which has supported life on this planet?

Plants are known as purifiers of air due to the process of:

Oxygen is $not$ produced during photosynthesis by

Sugars extracted from sugarcane and sugar beet differ in:

Statement $P$: During the dark reaction of photosynthesis,ketotriose is synthesized.
Statement $Q$: The sugar present in the structure of $ATP$ is an example of a ketopentose sugar.

The green part of the plant is primarily involved in which of the following processes?