Which two stages are involved in the process of photosynthesis?

• A. Glycolysis and Fermentation
• B. Light reactions and Calvin cycle
• C. Citric acid cycle and Electron transport chain
• D. Light reactions and Dark reactions

Answer: (B)

Photosynthesis consists of two distinct stages: the light reactions and the Calvin cycle. In the light reactions, which occur in the thylakoid membranes of chloroplasts, sunlight is captured and used to convert water and carbon dioxide into oxygen, ATP, and NADPH. This stage requires light energy, hence it is referred to as the light reactions.

Following this, the Calvin cycle takes place in the stroma of the chloroplasts, where ATP and NADPH produced in the light reactions are utilized to convert carbon dioxide into glucose. This stage does not require light directly, but it depends on the products of the light reactions to fuel the conversion of carbon dioxide into organic compounds.

The combination of these two stages forms the complete process of photosynthesis, allowing plants to convert light energy into chemical energy stored in glucose. The other options illustrate processes associated with cellular respiration or describe components of photosynthesis in less accurate terms, which do not fully capture the correct stages involved in photosynthesis.