Hi. In this video, we're going to be talking about the comparison of prokaryotes and eukaryotes. So I'm just going to zoom myself out of this, so you can see this entire table. This table is just a list of comparisons between prokaryotes and eukaryotes. I just want you to know how it's organized. The smallest structures are up here at the top and the largest ones are down here at the bottom. The smallest one we can start with is DNA, and it's fairly small. In prokaryotes, this is actually stored in a circular nucleoid, and in eukaryotes, it's in a linear chromosome. For DNA storage, for prokaryotes, this is free-floating in the cell, whereas in eukaryotes, it's in a nucleus that contains a nuclear envelope, so it's held inside a particular structure. Prokaryotes don't have a nucleus, and eukaryotes do. The same goes for internal membranes, which prokaryotes lack, but eukaryotes contain a complex cytoskeletal system. That includes microtubules, actin filaments, and intermediate filaments.
Now, we start getting to some processes. Prokaryotes divide by a process known as binary fission. For eukaryotes, this is through mitosis or meiosis. Once the cell divides, its daughter cell or its offspring, in prokaryotes contains a full copy of parental DNA. Whereas in eukaryotes, for meiosis, it only contains a half copy. You actually need parental DNA from two parents in order to produce offspring from a daughter cell in eukaryotes, not true in prokaryotes. Now, the largest difference here is the classification domain. In prokaryotes, it's Archaea bacteria whereas for eukaryotes, it is in Eukaryota.
If we look at specific images of two cells, we can look and compare what the similarities and differences are. One thing you will notice is that both have a cell membrane. You can see that the DNA is stored in the nucleoid of the prokaryote, where the DNA is stored in the nucleus of the eukaryote. The eukaryote also has all of these internal structures, which the prokaryote doesn't have. By looking at these images, we can compare back up to the table above and really examine what the similarities and differences between prokaryotes and eukaryotes are. Feel free to use this table to review either before a test or a quiz. I think it'll be really useful as we begin to understand the difference between prokaryotes and eukaryotes.
So now let's move on.
