Here's why:

* Chloroplasts are organelles found in plant cells and some algae. They contain chlorophyll, a green pigment that absorbs light energy.

* Photosynthesis is the process by which plants convert light energy into chemical energy in the form of sugars. This process takes place within the chloroplasts, specifically in the thylakoid membranes and the stroma.

So, while the entire plant can participate in photosynthesis, the chloroplast is the specific cellular location where the process happens.