Here's why:

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

* They have internal membranes: These membranes create compartments within the chloroplast, allowing for the specific reactions of photosynthesis to take place efficiently.

* They have their own DNA: This allows chloroplasts to replicate independently, ensuring they are present in sufficient numbers for the plant's needs.

Without chloroplasts, plants wouldn't be able to carry out photosynthesis and thus wouldn't be able to produce their own food.