Choose the correct answer from each of the four options given below:
The individual flattened stacks of membranous structures inside the chloroplasts are known as:
Topic: Grana and thylakoids
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(a) Grana.
Inside the chloroplast, flattened membranous sacs called THYLAKOIDS are piled into stacks called GRANA. The marking scheme accepts either term for this question.
WHY THE STACKING MATTERS: the thylakoid membranes hold the CHLOROPHYLL, and piling them into discs packs an enormous membrane area into a small volume — which maximises the light that can be absorbed.
THE DIVISION OF LABOUR inside one organelle: GRANA (thylakoids) — the LIGHT reaction; chlorophyll, photolysis, ATP and NADPH₂ STROMA — the DARK reaction; carbon dioxide fixed into glucose
Option (d) CRISTAE is the trap: cristae are the infoldings of the inner membrane of a MITOCHONDRION, not a chloroplast. Both organelles use folded membranes to increase surface area, which is why the words are confused.
Grana.