Mitosis:
* Purpose: Produces two genetically identical daughter cells. It's used for growth, repair, and asexual reproduction.
* Number of Divisions: One division
* Chromosomes: Starts with diploid (2n) parent cell and produces two diploid (2n) daughter cells. Chromosomes are duplicated once and then separated equally into two daughter cells.
* Genetic Variation: No genetic variation introduced. Daughter cells are genetically identical to the parent cell.
Meiosis:
* Purpose: Produces four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. It's used for sexual reproduction.
* Number of Divisions: Two divisions (meiosis I and meiosis II)
* Chromosomes: Starts with diploid (2n) parent cell and produces four haploid (n) daughter cells. Chromosomes are duplicated once, but separated twice (homologous chromosomes separate in meiosis I, sister chromatids separate in meiosis II).
* Genetic Variation: Introduces genetic variation through crossing over (exchange of genetic material between homologous chromosomes) and independent assortment (random alignment of homologous chromosomes during meiosis I). This leads to offspring with unique combinations of genes.
Here's a table summarizing the key differences:
| Feature | Mitosis | Meiosis |
|---|---|---|
| Purpose | Growth, repair, asexual reproduction | Sexual reproduction |
| Number of Divisions | One | Two |
| Daughter Cells | Two, diploid (2n) | Four, haploid (n) |
| Genetic Variation | None | Yes, through crossing over and independent assortment |
| Chromosomes | Duplicated once, separated once | Duplicated once, separated twice |
In essence, mitosis copies cells for growth and repair, keeping the genetic material the same. Meiosis creates gametes (sex cells) with half the number of chromosomes and a unique combination of genes, ensuring genetic diversity in offspring.
