Difference between Mitosis and Meiosis: 7 Key Differences
Mitosis and Meiosis walk into a bar. After a fun evening there, they decide to split the bill. Mitosis wants to split it in two ways and Meiosis believes a four-way split is fairer. If you don’t get the joke, don’t fret over it. By the time you are finished with this post, you’ll chuckle at this.
There is no point in delving into the differences between Mitosis and Meiosis without first going a bit into what they are. Both are part of cell division, but there is so much more to the story than that. Each one cell in the body duplicates and produces two more cells (daughter cells) each carrying exactly half of the genetic material of the initial cell. This division is a series of complex processes, each of them with impeccable timing and purpose so that each of the daughter cells receives the same amount of genetic material from the original cell. This set of processes is also called the cell cycle, and it is one of the most studied processes in molecular biology. The cell cycle is composed of two gap phases, G1 and G2, and S phase (S for synthesis) during which the genetic material is duplicated, and an M phase (M for mitosis) during which mitosis splits the genetic material into two resulting daughter cells. The cell divides.
Before we dive into the differences between mitosis and meiosis, let’s go into a bit more detail about the cell cycle. The G1 phase is where cells essentially regroup. Metabolic changes take place and pretty much ready the cell for the upcoming division. Once the final point is reached, also called the restriction point, the cell is ready for division and moves on into the S phase. The S phase, or the synthesis phase, is a time at which the genetic material of the cell is duplicated. It is said that each one chromosome has doubled and consists of two parts, also called sister chromatids. The G2 phase, another regrouping phase, is next. At this point, the cell carries twice the material and it needs to take a breather. During G2, the cytoplasmic material is assembled so that everything is ready for mitosis as well as subsequent cell division. Mitosis, also called the M phase, is intricate. It has two phases, nuclear division (mitosis) that is followed by cell division (cytokinesis). In other words, mitosis is the process whereby one cell divides into two separate cells, each of which contains the same amount of genetic material. Naturally, this delicate process is highly structured. Mitosis itself is composed of five stages, prophase, prometaphase, metaphase, anaphase and telophase. Each of these stages defines a process that brings the cell closer to as well as readies it for cell division.
Now that we have looked a bit into mitosis, it doesn’t hurt to take a look at meiosis so that we can go into the key differences at the end. Meiosis is essentially the process of producing sex cells with half the amount of genetic material as their parental cells. In genetic terms, haploid cells are formed from diploid cells. This process is subsequent to one DNA replication that is then marked by two successive nuclear and cellular divisions, namely Meiosis I and Meiosis II. Meiosis I is composed of leptotene, zygotene, pachytene, diplotene, prophase I, metaphase I, anaphase I, telophase I and subsequent cytokinesis. Meiosis II encompasses, prophase II, metaphase II, anaphase II, Telophase II and subsequent cytokinesis.
Meiosis also encompasses genetic diversity which it achieves via several processes that take place. These include the exchange of genetic material that happens between homologous chromosomes during meiosis I. Furthermore, maternal and paternal chromosomes align randomly in Meiosis I. Lastly, sister chromatids align randomly during Meiosis II.
Meiosis is also different between the genders. For males, Meiosis II culminates in four separate sperm cells, while for females the situation is a bit different. Meiosis II is finalized with three polar bodies and one mature egg cell.
1. Mitosis has just one phase, whereas meiosis has two phases.
2. Mitosis is the same in males and females, whereas meiosis differs based on gender.
3. Mitosis consists of five stages, while meiosis has ten phases that are then followed by cell division. This is because prophase in meiosis Ii’s divided into five phases rather than just one.
4. Mitosis has only one division of cells while meiosis has two divisions.
5. Mitosis is marked by two daughter cells that are genetically identical to the parent cell. Meiosis has four daughter cells, each of which has half the number of chromosomes. Daughter cells also genetically differ from the parent cells as well as each other.
6. Mitosis is the process that creates cells responsible for growth and repair, while meiosis makes gametes and ensures genetic diversity in sexual reproduction.
7. Meiosis includes a step during which chromosomes are paired. This means that chromosomes are very close together, and this enables crossing over of genes from one chromosome to another. This ensures genetic diversity. This does not happen during Mitosis.
So, you may wonder, why does the body go to such lengths to make all these processes as amazingly detailed as they are? Some pretty important things are taking place during both Mitosis and Meiosis, so it only makes sense that there are so many steps that compartmentalize responsibilities. By aligning them sequentially, the chances of error are much lower, and things are much easier to understand.
Also, let’s go back to the joke I told earlier. Mitosis and Meiosis walk into a bar. After a fun evening there, they decide to split the bill. Mitosis wants to split it in two ways, and Meiosis believes a four-way split is fairer. Get it now?