11. Cell Division
Introduction to Cell Division
11. Cell Division
Introduction to Cell Division
Introduction to Cell Division
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in this video, we're going to begin our introduction to cell division. Now. Cell division could be defined as the process of a single parent cell dividing or splitting into greater than or equal to two or mawr daughter cells. And so this term daughter cells, you'll hear your professor use it occasionally from time to time and you'll see it throughout your textbooks as well. And so this term daughter cells is really just referring to the cells that result from cell division or cell splitting now moving forward. In our course, we're going to talk about three main types of cell division, and we have these three main types number 12 and three down below. And, of course, the numbers in our text correspond with numbers that you see down below throughout our image. And so the first main type of cell division that we're going to introduce is called binary vision. And really, the most important thing that you should know about binary vision is that this is a type of pro carry ah tick cell division, and so on. Lee pro carry attic cells like bacteria or archaea are going to divide by binary vision but eukaryotic cells that do have a nucleus they do not divide by binary fission. And so let's take a look at our image down below, over here on the left hand side to clear some of this up and so notice that we're showing you an image of binary vision. And once again, binary fission is a type of cell division that Onley occurs in pro carry, ah, tick cells like bacteria or archaea that do not have a nucleus. And so notice here we're showing you a single parent, pro carry attic cell that does not have a nucleus and notice that it's DNA is just floating on the inside of the cell in the cytoplasm in a region called the nuclear oId, which that is review from our older lesson videos. But the big point here of binary vision is that it starts with a pro carry attic cell and noticed that by the end of the process there are two cells to pro carry attic cells, and so these two cells are turned the daughter cells, since thes air, the cells that result from the cell division and notice that each daughter cell down below has a copy of the DNA, which is in green, And that means that this original copy of the DNA is going to have to get replicated or duplicated at some point in this process. But we'll talk more about DNA replication later in our course and again, the biggest take away for binary fission is that this is how pro carry attic cells divide. Now, the other two types of cell division that we're going to introduce, uh, two and three are types of Eukaryotic cell division. And so we're gonna look at them specifically as they apply to the human life cycle. And so the second type of cell division that we're going to talk about is my toe sis. Whereas the third type of cell division that we're going to talk about is my yo sis. Now I'll admit at first glance, my toe sis and my oh sis, they sound really, really similar. And in fact, it turns out not only do they sound similar, but they also have a lot of similarities. But my toasts and my oh sis are different processes and so moving forward in our course, it's going to be very important for you guys to be able to distinguish between my toe Sis and my oh sis, now moving forward in our course were mainly going to try to break down mitosis first. But then, after we're done breaking down my toe, sis, then we'll switch over to discuss my Oh, sis. Now, just to give you a little bit of background information about my toasts and my oh, sis, my toast again is a eukaryotic cell division that is going to produce what are known as somatic cells. And somatic cells are really just body cells that do not get passed down to the next generation. And so somatic cells or body cells would include cells like our heart cells are liver cells and our skin cells. Now, human somatic cells are what are known as deployed cells, and we'll talk more about deployed later in our course. But really, what deployed means is that there are going to be two copies of every chromosome inside these cells, and so deployed is going to be symbolized using a symbol called to end. And so any time you see to end, you know that it represents a deployed cell, okay, and again you can think the end here represents the number of copies of chromosomes, and, of course, deployed cells have two copies of every chromosome. Now, my oh sis. On the other hand, the third type of cell division is also a eukaryotic cell division. But instead of producing somatic cells like might, assist does my oh Sis produces what are known as GAM, it's and game. It's are really just the fancy scientific name for sex cells such as the sperm and male and the eggs and females. Now human GAM. It's on the other hand, Unlike human somatic cells, they're not deployed, and so they don't have two copies of every chromosome. Instead, human gametes are what are known as hap Lloyd cells, and Hap Lloyd kind of sounds like half, so they have half the number of chromosomes. So instead of having two copies of every chromosome, they're only going to have one copy of every chromosome. And again, if this, uh, deployed and Hap Lloyd concept was a little bit difficult for you to understand, we're going to talk more about it later in our course. So this is more so of foreshadowing for you guys to get toe, understand these terms a little bit early. And so let's take a look at our image down below, over here on the right hand side to better distinguish my toe sis and my oh sis. And so what's important to note again is that this images showing the human life cycle so which you'll notice here at the top are two adults. Notice that there is a male and there is a female. And the males produce what our produce gametes Ah, that air called sperm cells. And so this process is going to be my Asus. My oh sis is the process that is going to produce the sex sells the gaming such as the sperm and the egg on the egg. Over here is the sex cell or the gaming of the female. Now notice that these gametes here are Hap Lloyd. They have the end symbol here, which represents half Lloyd, so that means that they have half the number of chromosomes. They only have one copy of every chromosome. And that's because during sexual reproduction, the sperm and the egg gametes are going to merge together in a process that's called fertilization. So you can see the sperm here merging with the egg, and they each have half the number of chromosomes. They each have one copy of every chromosome. So when they merge together, the resulting cell, which is called a zygote, ends up having two copies of every chromosome, so it becomes a deployed cell. And so the zygote here is a deployed cell, the very first sell off a human. And so this Zygo ends up growing and growing and growing into many trillions and trillions of cells through the process called mitosis and my toast. This is what takes a deployed cell and creates mawr deployed cells on. It allows the single cells I go to grow into a baby, and it also my toast. This will also allow the baby to grow up into a toddler and to grow up into a kid into a teenager and eventually grow up into a full adult either the male or the female, and notice that humans adults are all deployed so you can see the zygote is deployed. The baby has deployed cells, and the adults also have deployed cells which are to end and the only ones that air hap Lloyd are going to be the game. It's the sex cells, which are on Lee. Uh, well, I only have one copy of every chromosome. Now again, this here is just the introduction to Might Asus, which basically represents this entire green region here. And then my Oh sis, which represents the small section here of the life cycle and again moving forward in our course were mainly going Thio, introduce my toast this first. And then later in our course, we'll talk more about my Oh, sis. So this year concludes our introduction to cell division And again as we move forward in our course, we're going to get to learn a lot more about each of these cell division, so I'll see you all in our next video.
Which of the following statements about cell division is correct?
It is the process by which one parent cell divide into 2 daughter cells.
It is an unnecessary process once an organism reaches maturity.
It is the process by which two sex cells fuse.
It occurs in 2 stages of mitosis then meiosis in all types of cells.
Which one of the following best defines binary fission?
The process by which one cell splits into two cells.
The process by which one cell splits into four cells.
The process by which two cells combine to create a new cell.
The process by which gametes are created.
Asexual vs. Sexual Reproduction
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in this video, we're going to distinguish between a sexual and sexual reproduction. And so all living organisms must reproduce or generate mawr living offspring via one of two types of reproduction that we have number down below number one and number two. And of course, the numbers that you see up above here in the text correspond with numbers that you see down below in the image. Now the first main type of reproduction is a sexual reproduction. Now a sexual reproduction is, of course, going to mean that there's no sexual activity involved in the reproduction. And if you think about it, if there's no sexual activity involved, that means that there's Onley, one single parent involved in a sexual reproduction. And if there's only one single parent involved in a sexual reproduction, that means that there's Onley, one single source of the DNA from that one single parent. And if there's only one single source of the DNA, then that means that the offspring are all going to be genetically identical toe one another, because they're all going to be resulting from this single parent with only one source of DNA. Now, on the other hand, the second type of sex of reproduction is sexual reproduction. And, of course, sexual reproduction, as its name implies, means that sexual activity is involved. And when you think about it, of course, sexual activity means that they're going to be too parents involved in this type of reproduction instead of just one parent. And if there are two parents involved, that means that there are two sources of the DNA. One source of the DNA would be the father. The other source of the DNA would be the mother, and typically with sexual reproduction, the father and the mother do not have identical DNA. Their DNA is going to be different from one another. And so we have two different sources of DNA, and that's going to result in offspring that are genetically diverse from one another. And so they will not be genetically identical under most circumstances when it comes to sexual reproduction. Now let's take a look at our image down below to further distinguish between a sexual and sexual reproduction. Now, over here on the left hand side, these two images for binary fission and mitosis are falling under the category of a sexual reproduction because they do not involve any sexual activity. And again, that means that there's only one parent involved. And so notice that for both binary fission and my toe sis that the very beginning starts with just one single parent cell. And at the end of the process, it results in two daughter cells for both. But because there's Onley, one single parent cell involved in both binary fission and mitosis, they're both forms of a sexual reproduction. And because there's only one single parents sell, there's only one source of DNA, and the cells that result are going to be genetically identical to each other for both again binary fission and for the process of my toast is two daughter cells that air resulting are going to be genetically identical Now. This is not the case with this right side of the image over here, which is showing you sexual reproduction. And so sexual reproduction, of course, is going to involve two parents instead of one, so you can see the male parent over here and the female parent over here. And it's the process of my yos ISS not to be confused with my toe sis that forms the gametes or the sex sells, and because my oh sis forms the sex sells, my oh sis is more closely linked to sexual reproduction, since again it forms the sex, sells the sperm and the egg. And, of course, the sperm and the egg are going to fuse together to form the zygote, which ends up resulting in the individual, uh, the the the offspring, if you will. And so what's important to note about sexual reproduction is that it's going to create genetically diverse offspring. And we'll get to talk Mawr and Maura about these ideas as we move forward in our course. But for now, this here concludes our introduction to the difference between a sexual and sexual reproduction, and we'll be able to get some practice as we move forward. So I'll see you all in our next video.
Asexual reproduction differs from sexual reproduction in that:
Asexual reproduction produces genetically diverse offspring.
Asexual reproduction occurs only in bacteria.
Asexual reproduction produces offspring that are virtually identical.
Asexual reproduction does not occur in animals.
Importance of Cell Division
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So now that we've introduced the three main types of cell division binary vision, mitosis and my ASUs in this video, we're going to talk about the importance of cell division. And so cell division is an important process for reproduction, making more life, fetal development or growth. Allowing a single celled zygote to grow into a baby and allowing the baby to grow into a fully mature adult is through the process of cell division and also cell division is an important process for tissue repair. If you get a cut or something like that, uh, that tissue is going to die when you get that cut and so that dead tissue needs to be replaced. And that replacement, those replacement cells, come from the process of cell division and so down below. Here on the left hand side, we're showing you an image of a sexual reproduction, basically showing you how a single cell can divide to create two cells and so you can see the cell here is in the process of dividing. And so some cells rely on cell division for reproduction purposes, since many organisms are single celled, and the only way that they can create more life is through cell division now. Also, fetus development is going to be a critical. Uh, it's going to be a component. Um, that is a or cell division is going to be a critical component for fetus development, allowing a ah single cells. I go to grow into a fetus and allowing the fetus toe grow and develop into a ah baby and the baby to grow into a toddler and so on until the, um, full adult is formed. This is very important, and cell division plays a big role in the process of fetus development. And so here, in this images showing you, ah, single cell zygote here and how it can divide to form two cells. And then each of those condemn vied to form four cells and so on until there are trillions of cells allowing for the fetus to develop. And then once again, ah, cell division is very important for tissue repair and renewal. And so this is showing you an image of some cells that are dividing to help repair a specific tissue. And so cell division is very, very, very important is the main idea. Here and again, these are the main components that cell division is important for. But again, when a single cell divides to create two cells, each of those cells needs to have a copy of the DNA. And so that means that before a Selcan defied before any Selcan divide, it must first replicate or duplicate or make an extra copy of the DNA so that once again, each of the daughter cells that results can get their own copy of the DNA. And so, uh, the organization of the DNA is going to be a very important component to being able to understand cell division and how it works. So moving forward in our course, we're gonna start to talk about the organization of DNA inside of the cell, so I'll see you all in our next video.
Additional resources for Introduction to Cell Division
PRACTICE PROBLEMS AND ACTIVITIES (6)
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