Q.(a) Draw and label the structure of Chloroplast. OR

The chloroplast is a double-membrane plastid; its stroma houses stacked thylakoids (grana) connected by stroma lamellae, chloroplast DNA, ribosomes, and starch grains.

A hand-drawn figure cannot be rendered in this text format, so the structure is described part by part, exactly as it would be labelled in a diagram of a chloroplast in longitudinal/sectional view:

1. Outer membrane: a smooth, continuous membrane forming the outermost boundary of the chloroplast; it is freely permeable to small molecules.
2. Inner membrane: lies just within the outer membrane, separated from it by a narrow intermembrane space; it is more selectively permeable and regulates the passage of substances into the stroma.
3. Stroma: the semi-fluid, proteinaceous matrix filling the interior of the chloroplast (analogous to the mitochondrial matrix); it contains the enzymes of the Calvin cycle (the 'dark'/light-independent reactions of photosynthesis), as well as chloroplast DNA (a circular, naked molecule, since chloroplasts are semi-autonomous organelles), 70S ribosomes, and often starch grains (temporary storage of photosynthetic product).
4. Thylakoids: a third, internal membrane system suspended within the stroma, consisting of flattened, sac-like structures. Each thylakoid membrane houses chlorophyll, other photosynthetic pigments, and the protein complexes (photosystems, electron transport chain components, ATP synthase) responsible for the light reactions of photosynthesis. …