Though you can't easily see them using a light microscope, other organelles such as mitochondria are also streaming, along with the chloroplasts. Why do this? The streaming is thought to facilitate the transport of materials within, as well as between, cells. read more
They don't. They exist in the cells of plants and other photosynthetic beings. They are much like mitochondria or the Golgi within cells, and are classified as organelles. Not a lot of circulation to be had. read more
Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are highly dynamic—they circulate and are moved around within plant cells, and occasionally pinch in two to reproduce. read more
The chloroplast moves to cover more positions in the cell and optimize the absorption of light. This in turn will enable more production of glucose and therefore production of ATP. read more