Here's why:

* Chloroplasts contain chlorophyll: Chlorophyll is the green pigment that absorbs light energy from the sun, which is essential for photosynthesis.

* Photosynthesis takes place within the chloroplast: The chloroplast is the site where the light-dependent reactions and the light-independent reactions of photosynthesis occur.

Let me know if you'd like more information about photosynthesis or chloroplasts!