From a single fertilized egg to a full-fledged human body, the journey is planned by a single process called mitosis.Every cell in our body lives for weeks to a year, so what after the cell dies? We need new ones, which is the role of mitosis in our body to initiate replication of existing cells.Do you know what starts from zero and ends up at trillion? You and us! Yes, all of us, in fact, even plants and animals, come a long way from a tiny single cell to a thriving collection of thousands and thousands of cells, and each one of them is equally vital to keep us surviving. A single process of cell division brings about a wonder called life which is also why you are reading this post today!There are primarily two ways of cell division, namely meiosis, and mitosis. The former produces four separate cells called gametes, and the latter produces two clones of each cell with duplicated copies. These separated cells from both the processes further produce other child cells, which leads to the overall development of the organism’s cell.For more insights into the human body, have a look at these blogs, too; why do cells divide? And why do we need food?What is mitosis?We start as a zygote in our mother and now are a thriving community of cells working unanimously to keep us alive, which essentially implies that all of us have emerged from a single cell! The purpose of mitosis is to produce more genetically identical cells, which helps a body grow. The second and significant role of mitosis is to repair or replace worn-out cells. When we get injured, the cells at the injury site get damaged, so replication of damaged cells with healthy ones takes place through mitosis.Mitosis is another word with a Greek origin, which basically translates to a wrapping thread from ‘mitos’ and act or process from ‘osis’. The term is also an inspiration from the appearance of chromatin of cell nucleus that appears in the first stages of mitosis; it was coined by a German biologist called Water Fleming in 1887.In simple terms, mitosis refers to cell division by which the cell’s nucleus divides into two daughter cells. The cell division activity is not restricted to just us humans but all eukaryotic cells such as animals, fungi, and plants. The cell division is a continuous process taking place even as you are reading this now! Cell division in organisms is the reason they are alive as body cells continuously die. Our body can heal wounds or grow taller because it has the capability to produce new cells every day.Mitosis is a fundamental process in any organism practicing asexual reproduction like the amoeba since it is the only way to sustain their population and reproduce. The key element to split into two cells is, however, the nucleus. Thus the prokaryotes miss out on this beautiful process.What are the stages of mitosis? You’d think a simple activity that divides cells into two identical cells wouldn’t be too long or complicated, but here’s the deal, there are five phases of mitosis to actually create two daughter cells that are also genetically identical. The main aim of mitosis is to separate existing cells into two identical cells with equal numbers of chromosomes, but how does it all happen? The five phases of mitosis are the answer; let’s glance at them in brief.The first stage, prophase, consists of thick and shorter chromosomes that eventually condense to create sister chromatids. These are two identical parts that are connected to the centromere, an area of the chromosomes. The next step is the prometaphase that involves the dissolution of the nucleus and the chromosomes moving to the center of the cell. The mitotic spindle pulls the chromosomes apart, creating two daughter cells that are exact copies of their parent cell.Next comes the metaphase, where the replicated chromosomes move towards the outer part of each cell. In anaphase, which is the second last stage of mitosis, the chromatids begin to move away, resulting in individual chromosomes. When these chromosomes are formed and stop moving, the last stage that is the telophase commences. In this stage, a nuclear envelope is formed around each set of the newly formed chromosomes, and this is the cell membrane of the newly separated cell.Thus the two purposes of mitosis, one to form identical cells and the other to form identical cells with two copies of each chromosome, have reached. This procedure then repeats, allowing the body cells to renew or replace themselves time and again.What happens in each stage of mitosis?What we saw above was a brief of all prophase, prometaphase, metaphase, anaphase, and telophase, but a lot of science goes behind the duplicated number of cells forming in our body even now! So let’s dive into the nitty-gritty of mitosis.Before mitosis begins, there is a stage known as interphase, which essentially carries out duplication of DNA post which the cell enters mitosis. Prophase is the first step in mitosis wherein the DNA, or in other words, the number of chromosomes present in the cell is condensed. The replicated DNA strands called chromatin which is created during the interphase, are the strands that are condensed using histones. Histones are special proteins in a cell that allow these DNA strands to condense into tight packages, which could be moved around with ease while the cells get divided. Centrioles appear during prophase, which are centers on either side of the cell that organize microtubules. These microtubules subsequently grab the chromosomes of DNA. Plants have another additional step that rearranges the cell to put its nucleus in the middle in contrast to animal cells, where the nucleus is at the center of the cell by default.The microtubules reach out to them to grab the chromosomes and split them into two identical cells, for which the parent cell must permit them to go out. This is precisely mitosis’s second stage-prometaphase. The nuclear envelope in prometaphase, which is a membrane surrounding the cells, falls apart, separating the DNA from the cytosol of the cell. This makes way for the microtubules from centromeres to chromosomes and attaching themselves to chromosomes. A nerdy prometaphase fact for the nerds is that each chromosome has a unique area called the centromere, which has another part called the kinetochore. It is the kinetochore that the microtubules attach themselves to, which makes the chromosome mobile in the prometaphase.Next comes the metaphase, where an equal number of chromosomes are pulled at the center of the cell by the microtubules; this area is the metaphase plate. The body cells thus aligned on either side of the metaphase plate represent two copies of parent DNA. The cloned DNA in metaphase post division of the cells are sister chromatids that are the functioning genome of the newly divided cell. At this point, the nuclear envelope discussed earlier is also dissolved, and the mitotic spindle is attached to each of the chromatids.Anaphase is the penultimate stage in mitosis, which takes the least time to complete amongst the five stages. The sister chromatids that replicate the same DNA are initially connected, but during this phase, disjunction occurs, and the sister chromatids migrate away from each other to form daughter chromosomes. The simple reason behind this is that the proteins between these sister chromatids in each chromosome is eventually dissolved. ATP produced in the body shortens the spindle fibers attached to each chromatid, splitting the chromosomes into two sister chromatids. As these spindle fibers shorten, the daughter chromosomes or sister chromatids are further divided into half until they are at the opposite ends of the cell. This is where there is a diploid number of chromosomes at each pole of the cell.Finally, the last stage of mitosis occurs as the chromosomes get pulled towards each centriole. It is called telophase. They form a cleavage furrow in the cell. These chromosomes in telophase later get a nuclear envelope that surrounds each daughter cell, and thus the division of the parent cell finally results in two separate daughter cells. The centrioles dissolve, and each of the separate daughter cells resumes its respective cell functions. An important short step to know before the process of cell division ends in telophase is the beginning of interphase for the subsequent cell division. The process is known as cytokinesis. Once divided, the cells then resume growing.What is the purpose of mitosis and meiosis?As a science student, you will often come across the two terms mitosis and meiosis, which sound similar and create confusion, but fundamentally, they are very different. The most basic distinction being the kind of cells the two processes produce.To produce gametes is the main purpose of meiosis. These gametes are further incorporated into the sexual development of an organism’s body. In contrast, the purpose of mitosis is to give identical daughter cells that help in growth and repair. Meiosis, mitosis is both related in terms of cell division, but apart from that, there is a lot that distinguishes them; let’s have a sneak peek into their differences to understand them better.During meiosis, the diploid cells split into two cells and again split, resulting in four haploid cells. The new four haploid cells receive only a single copy of each chromosome from the parent cell, thus having just half the number of chromosomes as the parent cell. In fact, these haploid cells are nothing but gametes which are eggs in the case of a female and sperm in a male. Therefore the primary purpose of meiosis is to help an organism reproduce by producing gametes wherein each of the gametes would have half of the genetic complement of the parent cell.On the other hand, mitosis is necessary for three primary purposes, namely growth cell replacement, asexual reproduction, and development. Let’s walk through these in brief. Development and growth are about the emergence of new cells with the original chromosomal set preserved. This is nothing but the regular cell cycle in a plant’s, fungi, or animal’s body. Next comes the replacement of damaged cells when they are wounded or injured. New cells take their place and continue their functionality. This is how you or we recover from a fracture or small cut. Lastly comes asexual reproduction that applies to certain multicellular organisms and single-celled organisms. The reproduction in them occurs through fragmentation and budding. Plants also use mitosis to reproduce themselves.What is the purpose of mitosis in multicellular organisms?The fact that you can read this blog simultaneously, breathe, look around, feel the air and speak to someone is a culmination of many health factors, but do you know that all of those factors come down to a single process-mitosis. Mitosis is the answer to how a human body functions or any other multicellular organism. Here are a few highlights of the role played by mitosis in the cells of multicellular organisms.Genetic stability, one of the critical factors in the physical and mental development of a person or animal, is maintained through the simple procedure of dividing the parent cell into two identical cells. Each daughter cell formed contains chromosomes that are formed by copying the DNA. This ensures the two cells are formed as identical and uniform to the parent cell, and this is how a species of a certain kind survive by creating their own kind. Unfortunately, this process of genetic division at times could fail during the different phases of mitosis. For instance, there could be a situation where the chromosomes fail to separate during the anaphase or get damaged in the process, resulting in miscarriage or stillbirth. If the baby makes it alive, conditions such as leukemia, lymphoma, or Down syndrome may occur.Moreover, the answer to critical medical conditions such as cancer or tumor in multicellular organisms lies within the errors formed during various phases of mitosis. An error occurring while the DNA gets duplicated results in the two cells receiving different copies of chromosomes. Thus two copies of a cell’s DNA need to be present before a cell divides into corresponding daughter cells so that the resulting daughter cells have one complete copy of the cell’s DNA. When these cells create their own daughter cells, the failed copy of DNA continues to replicate, which potentially causes cancer.Ever wondered what makes your hair grow? Our hair keeps growing until one day we get tired and go to the salon to finally cut them! The answer again lies in the fascinating activity of mitosis. Growth in multicellular animals is inevitable, especially for specific important tissues with a high turnover of cells, such as hair and skin, controlled by the cell cycle. The cell cycle consists of DNA replication and cell division which is responsible for replacing old damaged cells with new identical cells.Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for what is the purpose of mitosis? Then why not take a look at why oil and water do not mix, or why scientists use models?
From a single fertilized egg to a full-fledged human body, the journey is planned by a single process called mitosis.
