Mitosis & Meiosis

Purpose of Mitosis

  • Function: Growth, repair, and replacement

    • Example: Skin cell replacement after sunburn or dryness (epidermis)

    • Example: Intestinal lining cells turnover every 3-4 days, replaced by mitosis.

  • Process of Mitosis:

    • Starts from a single cell and grows into a trillion-cell body.

    • Chromosome count: Starts with 46 chromosomes and ends with 46.

    • Key takeaway: Mitosis is for non-reproductive cell division.

Purpose of Meiosis

  • Function: Reproductive cell division

  • Outcome: Creation of gametes (sex cells) such as spermatozoa and eggs.

  • Location of Meiosis:

    • Occurs only in the primary reproductive organs (gonads): testes in males and ovaries in females.

  • Chromosome count in Gametes: 23 chromosomes (half of the genetic material).

    • Meiosis Process:

    • Consists of two cellular divisions leading to daughter cells with half the genetic material (23 chromosomes).

Differences between Mitosis and Meiosis

  • Mitosis:

    • No exchange of genetic material.

    • Produces identical daughter cells with the same chromosome number (46).

  • Meiosis:

    • Involves exchange of genetic material (recombination).

    • Produces genetically unique daughter cells with half the chromosome number (23).