Final answer:
Chloroplasts are organelles found in plant and algal cells that perform photosynthesis. They contain chlorophyll and thylakoids, and they convert light energy into glucose and oxygen.
Step-by-step explanation:
Chloroplasts are a type of organelle found only in the cells of plants and algae, and they perform photosynthesis. They contain the green pigment called chlorophyll, which is essential for capturing light energy and converting it into glucose and oxygen. Chloroplasts have a double membrane structure and are composed of thylakoids, which are fluid-filled sacs where the light reactions of photosynthesis occur.