CellXplorer is an interactive and annotated graphic that you can navigate. You can click on the buttons below to zoom in. You can also navigate to the lesson associated with that part of the cell in the HarvardX course on the edX platform! The graphic below can sometimes take some time to load.

Image above: 3-D rendered illustrations of prokaryotic and eukaryotic cells.

Left: Prokaryotic Cell. From the greek “pro” meaning “before” and “karyon” meaning “nut or kernel,” prokaryotic cells differ from eukaryotic cells in that they do not contain a membrane-bound nucleus or have other membrane-bound organelles with specialized functions. The endosymbiotic theory states that mitochondria originated from prokaryotes that were taken inside another cell as an endosymbiote around 1.5 billion years ago.

Right: Eukaryotic Cell. From the greek “Eu” meaning “true,” eukaryotic cells differ from prokaryotic cells in that they contain genetic material within a membrane-bound nucleus and have other membrane-bound organelles with specialized functions.