Mitosis is the process of dividing nuclear cells into two identical daughter cells. There are four stages: prophase, metaphase, anaphase, and telophase, followed by cytokinesis. Mitosis is important for cell reproduction, replacement, and regeneration, but problems can lead to genetic disorders and cancer. Meiosis differs from mitosis in that it occurs only in specific cells, results in genetically unique cells, and involves DNA from different cells.
Mitosis is the process of dividing nuclear cells. During division, the nucleus of the cell divides, resulting in two sets of identical chromosomes or organized DNA proteins. This process is almost always accompanied by a process called cytokinesis, in which the rest of the cell divides, resulting in two completely separate cells, called daughter cells. There are four stages in the process: prophase, metaphase, anaphase and telophase. There are a number of reasons for this process, including cell reproduction and replacement, and problems with it can seriously damage or kill cells. It is often confused with meiosis, but the processes differ in several ways.
stage
prophase
The DNA in the nucleus has already been duplicated in the previous stage of cell division, so when prophase begins, the nucleus contains two complete identical sets of DNA. At the beginning of prophase, chromatin, which is normally spread throughout the nucleus, begins to condense into an X shape, held together in the center by a specific DNA sequence called the centromere. Each half of the X is a replicated half of the DNA. Once they wrap together in the X, they are called mitotic chromosomes. Toward the end of prophase, the material enclosing the nucleus and cytoskeleton disappears, except in the case of some fungi, algae, and similar organisms, where the process occurs entirely within the nuclear envelope. This is called closed mitosis.
Once the material enclosing the nucleus dissolves, or, in the case of closed mitosis, after the DNA has formed into X, structures called centrioles move to opposite ends of the cell and help form a spindle apparatus of microtubules. which is essentially like strings running through the cell. Chromosomes also develop structures in between called kinetochores, which are later used to attach to microtubules.
metaphase
When prophase ends and metaphase begins, rope-like microtubules connect to the kineptchores on each side of the chromosome, so they can later separate them. The chromosomes line up with the spindle apparatus, which runs around the cell like the vertical lines on a globe. The soon-to-divide chromosomes are positioned symmetrically on the metaphase plate, which is essentially the mother cell’s equator. At the end of metaphase, each chromosome has microtubules attached to both of its halves, and they line up in a straight line along the cell’s equator.
anaphase
Once the chromosomes line up correctly, the spindle apparatus immediately separates the two identical halves of the DNA from each other and moves them to opposite sides of the cell. These two sets of chromosomes will develop into the nuclei of two daughter cells which are perfectly identical to each other and to the parent cell.
telophase
After the chromosomes get to the ends of the cell, they start unwinding and spreading again, as they were before forming into X. This is basically the opposite of the beginning of prophase. While this is happening, the spindle apparatus is broken. After that, the nuclear membrane, which encloses the nucleus, forms again around the chromosomes, unless it never dissolved in the first place, as in closed mitosis. Although this is the last stage, cell division is not complete until cytokinesis occurs.
Cytokinesis
Cytokinesis is the next stage in cell development and is similar to mitosis, except that it involves other parts of the cell instead of the nucleus. During this stage, the cell’s equator-like metaphase plate tightens, separating the cell into two new cells. Once completed, there are two functioning and identical cells.
Scope
One of the main purposes of this process is the natural growth of the parent organism. It is also done to replace cells that are worn out, damaged, or just at the end of their natural life. For example, a person is continually shedding dead skin cells, so the body has to divide the cells to make new ones. Some animals also use this process to regenerate parts of themselves, such as lizards that can regrow tails after losing them. Additionally, some animals undergo this process as part of asexual reproduction.
problematic
Problems with mitosis are devastating to cells and can lead to their death. Even if the cell doesn’t die, the chromosomes can be damaged or altered, which can lead to genetic disorders; Down syndrome, for example, is caused by a chromosomal problem related to mitosis. Also, damage to chromosomes or problems with the timing of how the cell divides can lead to growths and sometimes cancer. This can also happen if the chromosome is not separated properly.
meiosi
Mitosis and meiosis are both means of cell division, but they differ in a few key ways. First, meiosis occurs only in specific types of reproductive cells called gametes – in humans, eggs and sperm – and in spores. Also, in meiosis, the DNA from each contributing cell gets confused, with small pieces of DNA from different cells forming parts of the X. This is different from mitosis where the two halves of the X are identical. Furthermore, meiosis ends up with four cells that are completely genetically unique, whereas in mitosis, the end result is two completely identical cells.
Protect your devices with Threat Protection by NordVPN
