All the images show mitochondria a the shape of a short bean, more or less.
Now check out this fluorescent stain of mitochondria:
Instead of a bunch of short little football shapes, we see long, stringy networks of mitochondria within cells.
I’m embarrassed by how many times I’ve shown the artistic representations of the mitochondria in my classes. They’ve been mostly provided by textbook suppliers, but they are far from alone in getting it wrong, as the Google search shows. My colleague down the hall, Robert Gilkerson, works on mitochondria, tells me that researchers have known that mitochondria form these long, connected networks since the 1990s.
Weirdly, Wikipedia shows no less that four of the wrong “bean-like” pictures, then goes on to say:
Although commonly depicted as bean-like structures they form a highly dynamic network in the majority of cells where they constantly undergo fission and fusion.
Why do we keep perpetuating the wrong image? The artist’s renditions are very helpful in showing the double membrane structure of mitochondria, which is very relevant to function. But that could be shown in a more realistic representation of the structure, instead of copying from other textbooks.
I say “copy” deliberately, because there is clear evidence that undergrad biology textbook creators do copy from existing texts, sometimes for generations (Gould, 1991).
Gould SJ. 1991. The Case of the Creeping Fox Terrier Clone. Bully for Brontosaurus: Reflections in Natural History. W.W. Norton & Co.: New York.
Enhanced Yellow Fluorescent Protein (EYFP) Mitochondria Localization