Here's why:
* Chloroplasts contain chlorophyll: Chlorophyll is the green pigment that absorbs light energy, which is essential for photosynthesis.
* They have their own DNA: Chloroplasts have their own DNA, which allows them to produce some of the proteins they need for photosynthesis.
* They have a complex internal structure: Chloroplasts have a complex internal structure that allows them to carry out the different stages of photosynthesis.
While other parts of the plant are involved in supporting photosynthesis, the chloroplasts are the organelles specifically responsible for the process itself.
