Cyanobacteria, purple bacteria and green-sulphur bacteria are the 3 examples of photosynthesizing prokaryotes.
Step-by-step explanation:
The cyanobacteria are also called as oxygenic photoautotrophs. Although prokaryotes do not have well-defined chloroplast instead they have chlorophyll bound in vesicles.
They take energy from sunlight, absorb Carbon dioxide to make food and release oxygen in the process.