True or False: Photosynthesis occurs in both prokaryotic and eukaryotic organisms.

• A. TRUE
• B. FALSE
• C. Only prokaryotes
• D. Only eukaryotes

Answer: (A)

Photosynthesis is the process by which light energy is converted into chemical energy, and it isn’t limited to plants. In eukaryotes, chloroplasts house the photosynthetic machinery, with light reactions on the thylakoid membranes and the Calvin cycle in the stroma. Prokaryotes lack chloroplasts but still perform photosynthesis using their own membranes—often specialized internal membranes or the plasma membrane—to host the photosystems. Cyanobacteria are a key example of prokaryotes that carry out oxygenic photosynthesis, producing oxygen just like plants. Other bacteria can perform photosynthesis without releasing oxygen (anoxygenic) using different pigments. Because both prokaryotic and eukaryotic organisms can capture light to synthesize organic molecules, photosynthesis occurs in both groups.