In this image, we can see a piece of algae. The green portion of the image is the algae, which are photosynthetic eukaryotic organisms that mostly dwell in water. Algae lack the multicellular reproductive structures of true plants, and also do not have true roots, stems or leaves.

This sample was obtained with a dropper from the upper level of the Caltech turtle pond at 6:20 pm.

Algae are in the kingdom Protista, and the domain Eukarya. They are eukaryotes because their cells contain membrane-bound nuclei.