Life begins by the union of two cells known as gametes. These cells originate from the male and female parents, who produce the sperm and the ova. Within the gametes are structures known as chromosomes, which contain the genes. During fertilization, the gametes fuse and form a single cell known as the zygote, which carries 46 chromosomes.
If implantation occurs, the resulting zygote grows and develops through processes called mitosis and meiosis. With only a couple of letters separating the two words, each process is incredibly different, and confusing the two would significantly impact your understanding of cell division.
Differences Between Meiosis and Mitosis
Mitosis is when a cell duplicates its genetic material, resulting in two identical daughter cells containing 46 chromosomes.
Meiosis occurs when one cell with the correct number of chromosomes divides twice to produce four haploid cells (23 chromosomes). Each of the cells contains half the number of chromosomes as the parent cells.
Number of Daughter Cells
When mitosis occurs, it produces two daughter cells, each known as diploids. The diploid cells contain the same number of chromosomes as the parent cell.
When meiosis occurs, it produces four daughter cells, each known as haploids. The haploid cells contain half the number of chromosomes as the parent cell.
Where it Occurs
Mitosis occurs in all living organisms, except for viruses, while meiosis occurs only in plants, animals, and fungi.
Mitosis is useful in that it generates growth and repair of new cells when need be. Also, it is responsible for cell reproduction.
Meiosis is useful in that it facilitates genetic diversity resulting in new DNA. This is where natural selection comes to play to ensure only healthy, and strong organisms survive.
When mitosis occurs, there is no tetrad formation, while meiosis forms a tetrad during the prophase 1 stage.
Genetic Composition of New Cells
In mitosis, the new daughter cells are genetic clones because there’s no genetic crossing over of the cells.
In meiosis, genetic crossing over and recombination of the cells occur thanks to the random segregation of the homologous chromosomes.
Steps of Cell Division
There are only four cell division steps in mitosis: prophase, metaphase, anaphase, and telophase.
In meiosis, the same four steps named above get divided into several sub-steps: (Meiosis 1) Prophase I, Metaphase I, Anaphase I, Telophase I; (Meiosis 2) Prophase II, Metaphase II, Anaphase II, and Telophase II.
Mode of Reproduction
In mitosis, the mode of reproduction is asexual and takes place in sematic cells only. Examples of sematic cells are fat cells, blood cells, and skin cells.
In meiosis, the mode of reproduction is sexual, and it takes place in germ cells. Germ cells include any sex cell.
Mitosis and meiosis have distinct differences, as discussed above. Mitosis facilitates growth during the early stages of development and repairs/replaces worn-out cells during the late developmental stages. Meiosis, on the other hand, facilitates genetic diversity and the production of a new population.