Mitosis and meiosis are both types of cell division, but they have very different purposes and outcomes. Here's a breakdown of their key differences:
Key Differences Between Mitosis and Meiosis
| Feature | Mitosis | Meiosis |
|---|---|---|
| Purpose | Cell growth, repair, and asexual reproduction. | Sexual reproduction, generating genetic diversity. |
| Number of Divisions | One | Two |
| Daughter Cells | Two identical daughter cells. | Four genetically unique daughter cells. |
| Genetic Content | Daughter cells have the same number of chromosomes as the parent cell. | Daughter cells have half the number of chromosomes as the parent cell. |
| DNA Content | Daughter cells have the same DNA content as the parent cell. | Daughter cells have half the DNA content of the parent cell. |
| Genetic Variation | No genetic variation; daughter cells are clones. | High genetic variation due to crossing over and independent assortment. |
| Location | Occurs in somatic (body) cells. | Occurs in germ cells (cells that produce gametes: sperm and eggs). |
| Examples | Growth of a cut or wound, asexual reproduction in some organisms. | Production of sperm and eggs in animals and pollen and eggs in plants. |
Detailed Explanation
Mitosis
- Mitosis results in two identical daughter cells from a single parent cell.
- The daughter cells are genetically identical to the parent cell, meaning they have the same number of chromosomes and the same DNA content.
- This process is used for cell growth and repair. For example, when you cut your skin, mitosis is the process that creates new cells to heal the wound.
- It is also used for asexual reproduction in some organisms.
- Example: A hydra budding off a new individual is mitosis.
Meiosis
- Meiosis results in four genetically unique daughter cells from a single parent cell.
- The daughter cells have half the number of chromosomes and half the DNA of the parent cell.
- This reduction in chromosome number is crucial for sexual reproduction. When an egg and sperm fuse during fertilization, the resulting offspring has a full set of chromosomes, half from each parent.
- Meiosis creates genetic diversity through two main mechanisms:
- Crossing Over: During meiosis I, chromosomes exchange genetic material, leading to new combinations of genes.
- Independent Assortment: During meiosis I, chromosomes separate into daughter cells randomly.
- This genetic diversity is important for evolution.
- Example: The production of sperm cells in males involves meiosis.
As highlighted in the reference, "Mitosis produces two genetically identical ‘daughter’ cells from a single ‘parent’ cell, whereas meiosis produces cells that are genetically unique from the parent and contain only half as much DNA." (08-Sept-2021)
