Question

multiple choice question
nadph and atp are made during ____ and used during ____.

○ the light - independent reactions; the light - dependent reactions
○ chemiosmosis; the light - dependent reactions
○ the calvin cycle; chemiosmosis
○ the light - dependent reactions; the calvin cycle

Explanation:

To solve this, we recall photosynthesis stages: Light - dependent reactions (in thylakoids) produce NADPH and ATP using light energy. The Calvin cycle (light - independent, in stroma) uses these to fix $CO_2$ into glucose. Let's analyze options:

• Option 1: Light - independent (Calvin) doesn't make NADPH/ATP; light - dependent doesn't use them (it makes them), so wrong.
• Option 2: Chemiosmosis is part of light - dependent (makes ATP), but light - dependent doesn't use NADPH/ATP (it makes them), wrong.
• Option 3: Calvin cycle (light - independent) uses, not makes, NADPH/ATP; chemiosmosis is part of light - dependent (makes ATP), wrong.
• Option 4: Light - dependent makes NADPH/ATP; Calvin cycle (light - independent) uses them for carbon fixation, correct.

Answer:

D. the light - dependent reactions; the Calvin cycle (assuming the last option is labeled D, if original labels were A - D as per typical MCQ, with the last option being the correct one)