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What are the stacks of disc-like membranous sacs inside a chloroplast called?
publish date: 2026/06/15 18:20:22.451998 UTC
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Inside the chloroplast, the internal membrane system is organized into distinct stacked structures where the light-capturing reactions take place.
What are these stacks called?
Correct Answer
grana
Explanation
Grana (singular: granum) are the stacks of disc-like membranous sacs inside the chloroplast. Each disc is a thylakoid, and multiple thylakoids stacked together form a granum. The membranes of the grana contain chlorophyll and the other pigments and proteins involved in the light reactions of photosynthesis.
Reference
Biology: A Self-Teaching Guide