Question: what type of organisms does photosynthesis occur in?
Answer: In terms of organisms, photosynthesis occurs in autotrophes that contain the green pigment chlorophyll. This would include the entire plant kingdom, "half" of the Protista (the algae), & "half" the Moneran Kingdom (the blue-green algae). On the multicellular level, photosynthesis occurs in the leaves of plants.