The process by which a cell divides into two daughter cells is known as the cell cycle. In this process, the genome is duplicated, and other constituents of the cell are synthesised. Cell growth is a continuous process, but the synthesis of DNA synthesis takes place only at a specific phase in the cycle. Then, the duplicated chromosomes are distributed to the daughter cells by a sequence of events during cell division. These events take place under the control of genetics. Cell division can occur in two ways: mitosis meiosis. There are a few similarities between meiosis and mitotic cell division, but some major differences are also there.Â
Mitotic Cell Division
In mitotic cell division, the chromosomes replicate and are divided into two new nuclei. The cell gets divided once into two daughter nuclei. The total number of chromosomes remains constant in mitosis. Thus, Equational division is another term for mitosis. Mitosis takes place in four phases: Prophase, Metaphase, Anaphase and Telophase. During prophase, cell chromosomes get condensed, the nucleolus fades, and the mitotic spindle starts to form. In metaphase, chromosomes get aligned around the metaphase plate, i.e. the middle of the cell. During anaphase, the microtubules pull apart the chromosomes, which are then divided into two identical chromatids, which are genetically identical. These get attached to opposite ends of the cells. During Telophase, a new nuclear membrane is produced around each set of chromosomes. The nucleolus appears again, and the mitotic spindle fades. Then the cytoplasm divides into two genetically identical daughter cells.
Meiosis Cell Division
Meiosis is a type of cell division in which a single cell divides twice to produce four cells. The cells contain half of the initial amount of genetic information. These cells are reproductive cells, i.e. sperms in males and eggs in females. There are two stages of meiosis called meiosis I and meiosis II. Meiosis I happens in four phases. During prophase I, the duplicated chromosomes turn into X-shaped formations. The membrane around the nucleus dissolves, and the chromosomes get released. During metaphase I, the chromosomes get aligned around the centre of the cell, called the equatorial plate. During the anaphase, I phase, the pair of chromosomes are separated by the meiotic spindle. The meiotic spindle draws one of the chromosomes to one pole and the other one to the opposite pole of the cell. In Telophase I, two new nuclei are formed by the creation of a membrane around every set of chromosomes. The single cell is then divided from the middle and produces two different daughter cells.Â
Meiosis II also happens in four phases. In prophase II, there is a creation of duplicate centrioles, and the meiotic spindle gets produced again. During metaphase II, the chromosomes get aligned around the equatorial plate in each daughter cell. In anaphase II, the chromatids are dissociated and get formed into separate chromosomes.
In Telophase II, two new nuclei are formed by the creation of a membrane around every set of chromosomes. Post that, four cells are produced.
Difference Between Meiosis and Mitosis
The difference between meiosis and mitosis is listed below:
S.No | Topic | Meiosis | Mitosis |
1. | Cell Division | Two cell divisions occur. | One cell division occurs. |
2. | Daughter Cells | Four daughter cells are reproduced | Two daughter cells are produced. |
3. | Number of Chromosomes | The number of chromosomes becomes half of the original cell, known as haploid daughter cells. | The number of chromosomes remains the same as that of the original cell, known as diploid daughter cells. |
4. | Types of daughter cells | Meiosis produces daughter cells that are genetically different. | Identical daughter cells are produced. |
5. | Place of occurrence | Meiosis occurs only in plants, animals and fungi. | Mitosis takes place in all living organisms apart from viruses. |
6. | Cells Formed | Only germ cells are formed | All body cells are formed except germ cells. |
7. | Prophase Stage | Quite long prophase stage. | Very short prophase stage. |
8. | Recombination of Chromosomes | In meiosis, chromosomes can recombine during the prophase I stage. | Recombination of chromosomes does not take place during mitosis. |
9. | Metaphase Stage | During metaphase, pairs of chromosomes align up around the equatorial plate. | In mitosis, during metaphase, individual chromosomes are aligned around the metaphase plate. |
10. | Anaphase Stage | During anaphase I, the sister chromatids proceed to the poles together and get attached to the opposite poles during anaphase II. | During anaphase, the sister chromatids are attached to opposite poles. |
Conclusion
Cell division can occur in two ways: Mitosis and Meiosis. In mitosis, the chromosomes replicate and are divided into two new nuclei. The cell gets divided once into two daughter nuclei. In meiosis, a single cell divides twice to produce four cells. In mitosis, the number of chromosomes remains the same as that of the original cell. In meiosis, the number becomes half of the original cell. Mitosis produces identical daughter cells, while meiosis produces daughter cells that are genetically different. Mitosis takes place in all living organisms apart from viruses, while meiosis occurs only in plants, animals and fungi.