 not telling a fib. We looked at all those different kinds of cells and now I'm gonna tell you that there are two types and it's true. All cells can be categorized into one of these two types and I'm gonna write them down for you and then we're gonna look at this little image here. So the two types of cells that we are going to look at are prokaryotes. That's an R and eukaryotes and I'm showing you this picture because we are eukaryotes and when I think about a cell I think about a eukaryotic cell but most of number-wise most of the critters on our planet are actually prokaryotes and I'm showing you this little, I don't know if you can see this very well, let me see if I can get a highlighter. This is the eukaryotic line. Do you see that? And then what I'm showing you here is a evolutionary tree and you can see that this evolutionary tree we're going to say, oh you know I love evolutionary trees. So we will spend a lot of time talking about evolutionary trees and like how you read these things but basically this says that this is a common ancestor that little dot that I put on this tree. There was an ancestor at some point a single celled critter that gave rise to all of us and when you look at that you see I'm gonna just show you we have that little line of eukaryotes that actually like I could go in here and be like dude I think the eukaryotes like a sort of start arriving like here. So we're new and there aren't very many of us. Check out everybody else. Bacteria and their relatives these are all prokaryotes and there's another group called Archaeans and those are all prokaryotes. So just like most of my examples I get excited about humans and how we function and how ourselves function but really most of the diversity and lots of action is happening with things that aren't similar to us. Things that are prokaryotes. So let's look at what defines a prokaryote like what does that even mean? Fundamentally like the defining factor of prokaryotes and eukaryotes is that prokaryotes have no nucleus and eukaryotes have a nucleus and the nucleus contains DNA. It's important to know that even though prokaryotes bacteria Archea do not have a nucleus they do have DNA. They have instead it's called the nucleoid and it's the area where the DNA lives. Nucleoid is where the DNA is in a prokaryote. In the eukaryote we have a nucleus. If in doubt find out if the cell has a nucleus. If it doesn't it's a prokaryote. If it does it's a eukaryote done. That's it. You're done the story is over. There are some other characteristics that I'll just go ahead and add here. Prokaryotes when you think about bacteria they actually are much smaller and so do I have to write that eukaryotes are bigger? Sure I'm running out of room though. Prokaryotes do not have membrane found they know this is the know. No membrane bound organelles but euk's do have membrane bound organelles. I wonder if that is everything. I do want to tell you right now in that tiny little line of eukaryotes there are four main types of eukaryotes that we're gonna talk about to in detail today and I'm just gonna write them up here above the eukaryotes. Maybe I'll do this on both of both of these guys because the prokaryotes do you remember what I said what kinds of critters are prokaryotes? We had bacteria and we had archaea. Those were our types of prokaryotes and you're gonna know those so those are fair game for a question that I could ask you on a test or a quiz like and we'll talk about them a lot in this course. Eukaryotes the four that we're gonna know are guess, plants, animals, fungi, and watch I'm putting this in quotations. Protests. Protests are the only one that are single-celled. Sorry for this like mess of what? Rewrite your notes and get these concepts all organized into nice little structure of what these guys are. Protests are single-celled eukaryotes so we actually saw a bunch of those in our little walk of fame at the beginning of this lecture. All those big hairy single-celled critters with nuclei those are in the protist category. Protists are not closely related to each other which is why I put them in parentheses or I mean quotations that these are quotations not parentheses. I could put them in focus. They're not closely related to each other so there's a class or group of protists that are closely related to animals. There's a group of protists that are closely related to plants. We already saw the single-celled yeast a group a protist a single-celled organism that's really closely related to fungi. Next up now the way we're gonna tackle our cell parts we're gonna look at a bacterium and look for cell parts. We're gonna look at an animal and look for the cell parts and then we're gonna look at a plant and look for the cell parts. I think actually bacteria is the last thing that we're gonna look at. So this is how we're gonna go through and talk about what's in these cells. What what stuff do we find when we are looking in the cells. What organelles do they have and what are the functions of those organelles.