Binary Fission

In this video, we're going to begin our lesson on binary vision. And so recall from our previous lesson videos that pro Kerasiotes or pro carry attic organisms replicate by the process of binary vision. But you carry outs do not divide by binary vision. Recall that eukaryotes divide by mitosis. Now, binary fission can be defined as pro carry attic a sexual reproduction, meaning that there is only one single parental cell that will divide to form two new daughter cells. And the term daughter cells is referring to either of the two final cells that form after a cell divides. And so if we take a look at our image down below, notice on the left hand side, we're showing you our parental pro carry attic sell notice that its chromosome, which is here in blue is uh not within a nucleus. It is a circular chromosome. And so this is a pro carry attic cell. And so this single parental pro carry attic sell here. When it's ready to divide, it will divide by the process of binary fission. And the process of binary vision allows this single parental cell to divide into two daughter cells. And so we can label these here the daughter cells. And so the daughter cells once again are the final cells that result from binary fission here. And so this process of binary fission actually contains a few steps, critical steps that actually includes replicating the chromosome so that each of the daughter cells is able to get a copy of the chromosome. And so we'll be able to talk about some of the steps of binary fission in our next lesson video. But for now this year concludes our brief introduction to binary fission and I'll see you guys in our next video.

in this video, we're going to focus on the steps of binary fission. And so binary fission actually occurs in a series of multiple steps that can be consolidated down to just four steps. And notice that we have each of those four steps numbered down below in the text. And each of these numbers for each of the steps corresponds with the numbers for the steps that are down below in the image. Now, in the very first step of binary fission, the cell is going to elongate its cell envelope and so the cell wall itself membrane are all going to elongate and the cell is going to be increasing and its overall size. And all of this is going to happen as the D. N. A. Within the cell is going to get replicated, which means that the D. N. A. Is going to end up getting copied so that there are two identical copies of the D. N. A. And so if we take a look at our image down below At step number one notice that on the far left we have our pro carry Odjick parental cell and it only has one copy of the chromosome. However, in the first step of binary fission, the cell is going to elongate its cell envelope and so the cell wall and cell membrane are all elongated in comparison to the original parental. So, and as the cell is elongating, the D. N. A. Within the cell is also going to be replicated so that there are two identical copies of the D. N. A. And so notice here in this part of the image we have the replicating chromosome. So you can see this is the original chromosome and branching off of the original chromosome over here is going to be the other chromosome that is being formed now in Step number two, after the replicated uh after the replication of the DNA. To the replicated D. N. A. Is going to end up moving towards opposite ends of the cell. As a structure known as the septum begins to form. And so the septum is really just this structural partition, basically a divider that forms within the cell. Uh and it forms at the center of a dividing cell to end up separating the two resulting cells. And so if we take a look at step number two notice that the chromosomes are going to separate after replication. So this is the original one and this is the copied one over here. And so notice that they are separating into their separate cells. And you can see here that there's a structure that's beginning the form that's known as the septum. And so here we can say that the septum is beginning to form and once again the septum is this uh structure that is going to end up forming and dividing the cell. Mhm. So in step number three, the septum is going to completely form and create two separate cells that are still connected. And so, taking a look at step number three, notice that the septum is completely formed, it is complete. And so the septum once again, is this structural partition, this divider that forms to separate the two cells, This cell separating from this cell over here now. And step # four, the cells are going to completely separate from each other into two identical daughter cells. And identical means that these two cells are genetically identical, they have exactly the same DNA. And so if we take a look at step number four here in our image, notice that we're saying that the identical daughter cells are going to separate from one another. And so you can see here that we have this daughter cell is completely separate from this daughter cell over here and they are identical to each other genetically because they have exactly the same D. N. A. One that has been copied from the other. And so really this is the process of binary fission starting with a single pro carry attic parent cell And ending with two identical pro carry attic daughter cells. And so the actual amount of time that it takes for a cell to undergo binary fission is going to vary. And that specific amount of time that it takes for a cell to undergo binary fission is referred to as the generation time. How long does it take to create a new generation of cells? And so we'll be able to talk a lot more about this generation time later in a different video but for now, this year concludes our steps of binary fission, and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.