Meiosis is different from other forms of cell division. Unlike in other forms, the daughter cells in meiosis only have half the number of chromosomes of the parent. This means that the cells produced in meiosis are not exact copies of the original cell.
Meiosis is broken down into several stages. Each cell in the process of meiosis involves the cell growing, dividing, splitting, and dividing again in order to produce the four cells at the end of the process.
This cellular process is one of the more common processes of biology, but it is also the reason why people have some traits over others. Understanding meiosis is essential to understanding how organisms are created with certain aspects. If you want to learn more about cellular division or other concepts in biology, then check out the Udemy course, An Introduction to Basic Biology.
The First Stage of Meiosis: Interphase
Meiosis starts with the interphase. The interphase itself is broken up into different phases. The first phase of the Interphase is the G1 phase, which is the period before DNA gets synthesized. During this phase, the cell grows to prepare for cell division. An important thing to note is that the G in G1 stands for gap.
The next part of the interphase is the S or synthesis phase. In the S phase, DNA gets synthesized. This happens fairly quickly.
The final phase is the G2 or second gap phase. This is the part where the cell synthesizes proteins and continues to grow. This continues to happen until the start of the next phase.
Immediately after the interphase starts the prophase. There are several events that happen in the prophase. The first events involve the chromosomes condensing and attaching themselves to the nuclear envelope of the cell. Next, synapsis occurs, which is when a pair of chromosomes line up together. When this happens, tetrads are created, which are made of four chromatids. During this phase, it’s possible for crossing over to happen where the chromatids are moved and possibly rearranged.
After crossing over, the chromosomes start to get thicker and break away from the nuclear envelope. The centrioles will then move away and both the nucleoli and nuclear envelope will begin breaking down. This process is similar to mitosis.
The metaphase is pretty simple. The tetrads align at a plate. The centromeres are all oriented towards opposite poles of the cell.
The anaphase happens next, and it involves the chromosomes moving to opposite cell poles. The way this process works is through microtubules that pull the chromosomes and move them around the cell.
The telophase continues the processes of the previous phase in that the chromosomes are continuing their movement to the poles of the cell. After the movement is complete, each pole gets a haploid, or a complete set, of chromosomes.
When the Telophase ends, there are two daughter cells that are made. Each of these cells has exactly half the number of chromosomes from the original cell. There can be many different processes that happen in this phase in order for the cell to prepare for the second part of meiosis. The only constant is that the genetic material does not replicate, but instead it continues to get divided.
This is only the first half of meiosis. This process creates the first two cells that are then divided further into the final four cells of the process. When it comes to understanding the importance of biology, knowing the way cells divide is one of the first things you will learn. If you’re interested about the earlier stages of meiosis, you should check out the GCSE Biology course from Udemy.
The Prophase starts again in meiosis and the process involves the continual break down of both the nuclear membrane and the nuclei. The spindle network also appears. Again it is important to note that the chromosomes don’t replicate anymore, but they instead are simply broken down and separated further.
During this phase, the chromosomes start migrating again to the metaphase plate, which is located at the midpoint of the cell.
The second metaphase is just like the first. The chromosomes simply line up along the center of the cell before it splits in two. Again, the chromatids point towards the opposite ends of the cell.
The second anaphase is the penultimate phase in meiosis and it has a quite a few events that occur. The first event involves the sister chromatids separating and moving towards the opposite ends of the pole. The spindle fibers, at this time, will lengthen and enlarge the cell.
The paired chromatids will then begin to separate from each other. Every chromatid pair is considered to be a full chromosome.
Finally, the anaphase II starts preparing or the next and final phase of meiosis. Both of the cell poles start to move further apart and it can be seen at this point that the cells are splitting. By the end of this phase every pole will have a set of chromosomes.
The final phase in meiosis is the second telophase. Just like the first one, the telophase involves the cell breaking apart into four daughter cells. The nuclei can be clearly seen in this phase. You can also see cytokinesis during this phase, or the division of the cytoplasm.
Once the second Telophase is done, meiosis is complete. The end result, as mentioned before, is four daughter cells. Each individual cell has half the amount of chromosomes that the original cell once had.
The Purpose of Meiosis
The purpose of meiosis is reproduction. All living organisms are able to reproduce, and when they reproduce different characteristics are passed onto the offspring. Scientifically, meiosis reduces the diploid cells, which has two copies of every chromosome in a cell and makes it haploid cells, which instead hold a single copy of each chromosome per cell.
The reason why the offspring in different animals and plants have different characteristics is because they don’t inherit the same DNA from one parent, but instead they inherit a few genes from each parent. Through the process of meiosis organisms can grow and change over time.
The Future of Biology
Today, there are studies that delve deep into biology and reproduction. These studies are designed to help people understand how human life is created and the process that cells go to create that life. There are several advancements in the use of technology in biology. This is called biotechnology, and it is designed to help improve the way of life for biological organisms.
Examples of biotechnology include creating artificial organs for humans or prosthetic limbs. There are efforts to take biotechnology to further levels in which technology can potentially cure serious illnesses. People are even working towards taking certain forms of technology and using it to make changes to organisms on a cellular level.
If you want to learn more about biotechnology and how it is used in various biological processes, such as meiosis, check out the Udemy course Biotech Basics.
Biology and Other Sciences
Biology is important for studying all sorts of sciences. If you’re interested in studying medicine, then it is important to understand how biological processes, such as meiosis are done. If you want to go to school to study medicine, you can check out the Udemy course How to Get Into Medical School.