Meiosis ll : Equational Cell Division (original) (raw)
Last Updated : 23 Jul, 2025
**Meiosis II is the second phase of thecell division that separates the sister chromatids. Meiosis II is also known as **equational cell division because the chromosome number at the end of meiosis II remains the same as at the end of meiosis I. It is a similar process of mitosis but genetic results are different for this process. In this process, a haploid parent cell divides into four genetically different haploid cells with non-duplicated chromosomes. Meiosis is responsible for forming the sperm and egg cells. This stage generally ensures genetic diversity. The process of meiosis consists of two stages: Meiosis I and Meiosis II. In this article, we will discuss Meiosis II and the different stages related to it.
Table of Content
- Meiosis II
- Meiosis II - Pictorial Representation
- Stages of Meiosis II
- Significance - Meiosis II
- What is Meiosis?
- Why Meiosis is called the Reductional Division?
- Difference Between Meiosis I and Meiosis II
Meiosis II
Meiosis II is the second stage of **meiosis which is a specific cell division. It occurs specifically in the sexually reproducing organisms. The stage is responsible for the formation of gamete cells to sustain sexual reproduction. Meiosis II is also responsible for the genetic diversity in sexually reproducing organisms, particularly humans. In this process, a diploid parent cell divides into four genetically different haploid cells with non-duplicated chromosomes.
Meiosis II Diagram
At the time of Meiosis II, two haploid (n = 2) cells divide into four haploid (n = 2) cells. It is an important thing that these four haploid cells are genetically different from each other. In humans (2n = 46), we have 23 pairs of chromosomes. From the beginning till end, the number of chromosomes remains unchanged during the process of Meiosis II (n = 23).
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**Stages of Meiosis II
Meiosis II is also known as **equational cell division because it does not affect the chromosome number. The process leads to the formation of haploid cells. In this phase, two haploid cells go through further division which were created during the DNA replication process in the Meiosis stage I. Here are the four major stages of Meiosis II as mentioned below:
**Prophase II
Prophase II starts after the process of cytokinesis of meiosis 1. In this stage, the daughter cells develop and get ready for the second round of division. At this phase, the spindle fibers develop after breaking the nucleus. The chromosomes become more condensed at this stage. At this phase, the nuclear membrane starts to disappear with the Golgi apparatus and ER complex.
Metaphase II
In Metaphase II, the chromosomes start to connect with the centriole through the microtubules. The chromosomes start to align along the middle of the metaphase plate.
Anaphase II
At the time of Anaphase II, the chromosomes start to split from the middle. The sister chromatids start moving to the opposite poles of the cell. The leading edge of the kinetochore pulls chromatids to the poles.
Telophase II
In Telophase II, the chromosomes start to dissolve again. At this phase, the chromosomes reach the opposite side completely. The cell divides into four unique haploid cells. It is the end of the entire meiosis process.
**Significance of Meiosis II
The process of Meiosis II isresponsible for the formation of gamete cells to sustain sexual reproduction. Here are the major significance of this particular stage as mentioned below:
- Meiosis II ensures the same number of chromosomes distribution in sexually reproducing organisms.
- The haploid gametes develop from a diploid cell.
- These gametes fuse afterward to create a new diploid cell.
- It also supports the restriction of chromosomal expansion.
- With Meiosis II, it is possible to preserve the stability of a particular species.
Difference Between **Meiosis I and **Meiosis II
Here we are going to discuss about the major differences between **Meiosis I and **Meiosis II:
| Aspects | **Meiosis I | **Meiosis II |
|---|---|---|
| Purpose | Reductional division | Equational division |
| Preceding Events | Preceded by interphase | Preceded by Meiosis I |
| Number of Divisions | One | Two |
| Starting Cells | Diploid cells (2n) | Haploid cells (n) |
| Homologous Chromosomes | Homologous chromosomes pair and undergo crossing over | No crossing over, sister chromatids separate |
| Resulting Cells | Two haploid cells (n) with unique combinations of chromosomes | Four haploid cells (n), each genetically distinct |
| Chromosome Number | Halves the chromosome number | Maintains the chromosome number |
| Synapsis | Occurs during prophase I | Absent |
| Crossover | Occurs during prophase I | Absent |
| Separation of Chromatids | Homologous chromosomes separate | Sister chromatids separate |
| Genetic Variation | Increases due to crossing over and random assortment | Maintains genetic information from Meiosis I |
What is **Meiosis?
Meiosis is a specialized cell division process. It helps to produce gametes in sexually reproducing organisms. The meiosis process divides a particular cell by following two rounds that result in the creation of four genetically different haploid cells with non-duplicated chromosomes.
Why is meiosis called Reductional Division?
Meiosis is called the reductional division because the daughter cell's chromosomes reduced to half of the parent cell. Meiosis is a special type of cell division. In this, each daughter cell receives half of the chromosomes from the parent cell after division. It means, the haploid daughter cells (n) are formed from a diploid parent cell (2n) during the process of cell division.
Conclusion
At the end of meiosis II, the chromosome number remain same. It is the second stage of meiosis. It occurs specifically in the sexually reproducing organisms. At the time of Meiosis II, two haploid (n = 2) cells divide into four haploid (n = 2) cells. It is an important thing that these four haploid cells are genetically different from each other. In humans (2n = 46), we have 23 pairs of chromosomes.
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