Question

1. the light reactions of photosynthesis occur in the thylakoid membranes and the ____ ____ takes place in the stroma.

Explanation:

Photosynthesis has two main stages: light - dependent reactions (light reactions) and light - independent reactions (Calvin cycle or dark reactions). Light - dependent reactions occur in the thylakoid membranes, and light - independent reactions (Calvin cycle) occur in the stroma of the chloroplast. So the first two blanks are "light" and "reactions", and the last two blanks should be "light - independent" (or "dark") and "reactions" (or "Calvin cycle" can also be used, but in the context of the sentence structure, "light - independent reactions" fits well).

Answer:

The \underline{light} \underline{reactions} of photosynthesis occur in the thylakoid membranes and the \underline{light - independent} \underline{reactions} (or \underline{dark} \underline{reactions}, or \underline{Calvin} \underline{cycle} in some contexts) takes place in the stroma.