Explanation:

Chloroplasts exist in the cytoplasm of plant cells. They are flat, Frisbee-shaped structures filled with thylakoids. Thylakoids are small disk-like compartments composed of membranes that are the sites of sunlight-dependent photosynthesis. The thylakoids are surrounded by the stroma, or the inner liquid portion of the chloroplast. Both the stroma and the thylakoids contain important molecules for photosynthesis. Thylakoids are often stacked on top of each other - they look like a stack of flapjacks. Grana, or singular 'granum,' are stacks of thylakoids within chloroplasts.