1. Ploidy:
- Mitosis: Mitosis produces genetically identical daughter cells that are diploid (2n), meaning they have two copies of each chromosome, one inherited from each parent.
- Meiosis: Meiosis results in haploid (n) cells through two successive divisions, each with chromosome segregation and recombination events. The resulting gametes (such as egg or sperm) contain half the number of chromosomes compared to the parent cell.
2. Genetic Diversity:
- Mitosis: Since daughter cells in mitosis are genetically identical, they carry the same genetic information as the parent cell.
- Meiosis: Meiosis involves several steps that foster genetic diversity among offspring:
- Crossing Over: During the first meiotic division (meiosis I), homologous chromosomes pair and exchange genetic material through a process called crossing over. This leads to genetic recombination, resulting in chromosomes with new combinations of maternal and paternal genes.
- Independent Assortment of Chromosomes: During meiosis I, homologous chromosomes segregate and assort independently to opposite poles of the cell. This means different combinations of maternal and paternal chromosomes can end up in gametes.
- Random Fertilization: In sexual reproduction, fertilization involves the random fusion of haploid gametes contributed by two parents. The combination of diverse gametes further contributes to genetic variation in offspring.
3. Number of Daughter Cells:
- Mitosis: Mitosis produces two diploid daughter cells.
- Meiosis: Meiosis results in the formation of four haploid daughter cells (gametes) after the completion of both meiotic divisions.
4. Purpose and Location:
- Mitosis: Mitosis primarily functions in cell growth, repair, and asexual reproduction, and occurs in somatic (body) cells.
- Meiosis: Meiosis is a specialized cell division involved in sexual reproduction, leading to the formation of gametes in reproductive organs (ovaries and testes).
These fundamental differences in cellular formation through mitosis and meiosis are essential for genetic variation and the passing on of genetic traits from one generation to the next during sexual reproduction.
