Question

What are the main differences between mitosis and meiosis?

Answer 1

Mitosis and meiosis are two types of cell division that serve different purposes in organisms. Here are the main differences between them:

### Purpose:
- **Mitosis**: Primarily responsible for growth, repair, and asexual reproduction in organisms. It produces two identical daughter cells.
- **Meiosis**: Specialized for sexual reproduction. It produces gametes (sperm and eggs) and results in four genetically diverse daughter cells.

### Number of Divisions:
- **Mitosis**: Involves one round of division (prophase, metaphase, anaphase, telophase).
- **Meiosis**: Consists of two rounds of division (Meiosis I and Meiosis II), which includes stages similar to mitosis.

### Chromosome Number:
- **Mitosis**: Maintains the same chromosome number as the original cell (diploid to diploid or haploid to haploid).
- **Meiosis**: Reduces the chromosome number by half (diploid to haploid), resulting in cells that carry only one set of chromosomes.

### Genetic Variation:
- **Mitosis**: Produces genetically identical daughter cells (clones) unless mutations occur.
- **Meiosis**: Introduces genetic variation through processes like crossing over (homologous chromosomes exchange genetic material) and independent assortment (random distribution of chromosomes to gametes).

### Number of Daughter Cells:
- **Mitosis**: Produces two daughter cells.
- **Meiosis**: Produces four daughter cells.

### Stages of Division:
- **Mitosis**: Consists of one set of phases (prophase, metaphase, anaphase, telophase).
- **Meiosis**: Involves two sets of phases:
- **Meiosis I**: Homologous chromosomes pair up and separate.
- **Meiosis II**: Sister chromatids separate, similar to mitosis.

### Crossing Over:
- **Mitosis**: There is no crossing over or pairing of homologous chromosomes.
- **Meiosis**: Crossing over occurs during prophase I, contributing to genetic diversity.

### Role in Organisms:
- **Mitosis**: Affects somatic (body) cells.
- **Meiosis**: Affects gametes and is crucial for sexual reproduction.

These differences are fundamental for understanding how organisms grow, repair tissues, and reproduce.