Mitosis and meiosis are two distinct processes of cell division, and they differ in several key aspects:
Purpose:
- Mitosis: The primary purpose of mitosis is to produce two genetically identical daughter cells from a single parent cell. It is involved in growth, repair, and asexual reproduction.
- Meiosis: Meiosis, on the other hand, is aimed at producing gametes (sperm and eggs) for sexual reproduction. It results in four genetically diverse daughter cells, each with half the number of chromosomes of the original cell.
Number of Divisions:
- Mitosis: Involves one round of division, resulting in two daughter cells.
- Meiosis: Involves two rounds of division (Meiosis I and Meiosis II), resulting in four daughter cells.
Chromosome Number:
- Mitosis: The daughter cells have the same diploid chromosome number as the parent cell (e.g., humans have 46 chromosomes).
- Meiosis: The daughter cells have half the chromosome number of the parent cell (haploid), leading to 23 chromosomes in humans.
Genetic Variation:
- Mitosis: The daughter cells are genetically identical to each other and to the parent cell (unless mutations occur).
- Meiosis: The daughter cells are genetically diverse due to processes like crossing over (exchange of genetic material between homologous chromosomes) and independent assortment of chromosomes.
Phases:
- Mitosis: Involves prophase, metaphase, anaphase, and telophase, followed by cytokinesis.
- Meiosis: Consists of two rounds of division with phases including prophase I, metaphase I, anaphase I, telophase I (resulting in two cells), followed by prophase II, metaphase II, anaphase II, telophase II (resulting in four cells).
Pairing of Homologous Chromosomes:
- Mitosis: Homologous chromosomes do not pair up.
- Meiosis: Homologous chromosomes pair up during prophase I, which facilitates the process of crossing over.
In summary, mitosis is about growth and maintenance of somatic cells, creating identical cells, while meiosis is specialized for producing gametes with genetic diversity for sexual reproduction.