DENDROLOGY

Detailed explanation-1: -hollow disks that are called thylakoids (“saclike”). The chloroplasts of most higher plants have regions, called grana, in which the thylakoids are very tightly stacked. When viewed by electron microscopy at an oblique angle, the grana appear as stacks of disks.

Detailed explanation-2: -Photosynthesis takes place inside the chloroplasts that sit in the mesophyll of the leaves. The thylakoids sit inside the chloroplast and they contain chlorophyll which absorbs the different colours of the light spectrum to create energy (Source: Biology: LibreTexts).

Detailed explanation-3: -The thylakoid membrane forms a network of flattened discs called thylakoids, which are frequently arranged in stacks called grana. Because of this three-membrane structure, the internal organization of chloroplasts is more complex than that of mitochondria.