Overview of Mitosis and Meiosis

Mitosis

• Definition: Process of cell division resulting in two identical cells.
• Starting Cell: Diploid (2n) with 46 chromosomes (23 from mother, 23 from father).
• Process:
  • Cell undergoes interphase (growth, DNA replication).
  • Mitosis occurs, followed by cytokinesis.
• Outcome:
  • Two cells, each diploid (2n).
  • Cells are genetically identical to the original cell.
  • Cells can cycle back to interphase and repeat the process.
• Function:
  • Responsible for growth and repair of tissues in organisms.

Meiosis

• Definition: Process of cell division that produces gametes (sex cells).
• Starting Cell: Diploid (2n) with 46 chromosomes.

Meiosis Process

1. Interphase:

   • Cell replicates its DNA.

2. Meiosis I:

   • Results in two cells, each with a haploid (n) number of chromosomes (23 for humans).
   • Homologous pairs are split, leading to genetic variation.

3. Meiosis II:

   • Similar to mitosis, but starts with haploid cells.
   • Results in four haploid cells (gametes).

Key Characteristics of Meiosis

• Outcome:
  • Four haploid cells that do not necessarily have the same genetic information.
  • Each gamete is unique due to genetic recombination during Meiosis I.
• Not a Cycle:
  • Unlike mitosis, meiosis is not a continuous cycle.
  • Gametes are used in fertilization to create a fertilized egg.

Role in Reproduction

• Gametes:
  • Male: Sperm cells produced in testes.
  • Female: Egg cells produced in ovaries.
• Fertilization:
  • Gametes fuse during sexual reproduction to form a zygote.

Location in the Body

• Somatic Cells:
  • Make up most of the body.
• Germ Cells:
  • Involved in meiosis, located in testes (males) and ovaries (females).
  • Germ cells can undergo mitosis to produce more germ cells or meiosis to produce gametes.