 Tracic! Hey everybody, Dr. O here. In this short video I'm just going to talk about the different arrangement of flagella you might see. So first, just a reminder what flagella do. They're contractile and they're used for movement. So you can see one of them, like you see here on the far left, you can see a whole bunch of them. So the first group you actually don't see here is called atrychus. So bacteria that don't have a flagella would be atrychus. Then you see, so all bacteria that have flagella are either going to be polar or paratrychus, which we'll end with, but polar just means on one or both ends. You would see the flagella. So first group here we have is the monotrychus. That's going to be a single mono, single flagella on one end. So amphotrychus, ampha means both, I think of like amphibians, how they can live on water and land. So amphotrychus means that you're going to have flagella on both ends. Now you can have one or several. So amphotrychus flagella on both poles, on both ends. This means a tuft of flagella on one end. And then lastly we have paratrychus. So paratrychus means all over the place. Now this picture doesn't do it justice. This could have hundreds or hundreds of flagella even on the surface. So I remember how important flagella are for bacterial movement because since they're so tiny, bacteria moving through water would be like you trying to swim through peanut butter. So just one last kind of cool thing, the paratrychus flagella just all over the place. This has even been used like in movies like The Matrix to make like these, I think they're called sentinels, these like alien robot creature things or whatever they are. But they're actually not only their structure but how they move, the run and tumble, which we'll cover in a separate video, is actually what they were modeled after. So it's kind of interesting. Okay. Atrychus, no flagella. Monotrychus, one flagella on one pole, on one end. Amphotrychus, flagella on both ends. Lofotrychus, a tuft of flagella on one end. And then if you have back flagella all over your paratrychus. Okay. Have a wonderful day. Be blessed.