* They convert light energy into chemical energy. This is the fundamental process of photosynthesis.

* They contain chlorophyll. Chlorophyll is a pigment that absorbs light energy, specifically in the red and blue wavelengths.

* They use water as a source of electrons. Water is split to provide electrons for the electron transport chain in photosynthesis.

* They release oxygen as a byproduct. Oxygen is released as a result of splitting water molecules.

* They possess specialized structures for photosynthesis. These structures vary depending on the organism, but they all contain chlorophyll and the necessary enzymes for the process.

While all photosynthetic organisms share these features, they can be very diverse in other aspects. For example, they can be:

* Unicellular or multicellular: Photosynthetic bacteria are unicellular, while trees are multicellular.

* Eukaryotic or prokaryotic: Plants are eukaryotic, while cyanobacteria are prokaryotic.

* Aquatic or terrestrial: Algae live in water, while plants live on land.

Even though they are diverse, the common thread for all photosynthetic organisms is their ability to harness the energy of light to produce food. This process is essential for life on Earth, as it provides the basis for all food webs.