True
The stacked thylakoids are disk-shaped, interconnected membranous sacs embedded in the membrane of the stroma.
The stacked thykaloids are disk-shaped membrane-bound structures that are firmly fixed in the chloroplast stroma. The stacked thylakoids are also called grana and they are joined by either stroma thylakoids or lamellae, which links granum stacks together as one functional part. About 10 to 100 grana can be present in the chloroplasts.