The first picture in the Big Bang Theory Opening after the initial 3D universe expanding is very recognizable by lots of people, even though they might not know what it actually is:

This is an image of mitosis - specifically, the Anaphase of mitosis. You can see what I am pretty sure is the original stock image here - the one on screen is monochromed and rotated. Mitosis is what makes life possible - without cells splitting to create new cells, we would not have any life at all. In single cell organisms, it is the entire reproductive process. In this way, I think it’s a pretty good image to start it all out with. This specific image is probably of onion tip mitosis, which produces cells which look pretty much exactly like this. You can tell it’s a plant because there are some really nicely defined cell walls there.

This is the first in a (hopefully) long series of posts in which I am attempting to identify all of the pictures in the opening credits of The Big Bang Theory. I’ve done some minor searching on the web for something of this nature but haven’t found anything, and I’m always wondering what the heck all of those pictures flying by in the second half of the intro are actually. I’ve decided to start at the beginning, mostly because the pictures will be easier to identify.