10. Differentiate between mitosis and meiosis.|

### 1. Definition - **Mitosis** is the process of cell division through which a single cell divides to produce two genetically identical daughter cells. - **Meiosis** is the process of cell division that reduces the chromosome number by half, resulting in four genetically distinct daughter cells, typically involved in the production of gametes (e.g., sperm and eggs). ### 2. Purpose and Function - **Mitosis:** - Produces cells for growth, repair, and asexual reproduction. - Maintains the same ploidy (i.e., if the parent cell is diploid \(2n\), the daughter cells are also diploid \(2n\)). - **Meiosis:** - Produces gametes for sexual reproduction. - Reduces the chromosome number from diploid \(2n\) to haploid \(n\) in each gamete, ensuring that when two gametes unite during fertilization, the original diploid number is restored. ### 3. Number of Divisions and Outcome - **Mitosis:** - Involves one division cycle. - Results in two daughter cells that are genetically identical to the parent cell. - **Meiosis:** - Consists of two successive division cycles, called Meiosis I and Meiosis II. - Results in four daughter cells, each genetically distinct from the parent cell and from each other. ### 4. Genetic Variation - **Mitosis:** - No crossing over or recombination occurs, so the daughter cells have identical genetic information as the parent cell. - **Meiosis:** - Crossing over occurs during prophase I, where homologous chromosomes exchange genetic material. This leads to genetic recombination. - Independent assortment during metaphase I also contributes to genetic variation among the daughter cells. ### 5. Synapsis of Chromosomes - **Mitosis:** - Homologous chromosomes do not pair up. - **Meiosis:** - Homologous chromosomes pair up during prophase I (a process known as synapsis) which facilitates crossing over. ### 6. Summary Table | Feature | Mitosis | Meiosis | |------------------------------|---------------------------------------------|-------------------------------------------| | **Purpose** | Growth, repair, asexual reproduction | Production of gametes for sexual reproduction | | **Number of Divisions** | One | Two | | **Number of Daughter Cells** | Two | Four | | **Genetic Identity** | Daughter cells are identical | Daughter cells are genetically different | | **Ploidy** | Maintains \(2n \to 2n\) | Reduces \(2n \to n\) | | **Crossing Over** | Does not occur | Occurs during prophase I | Each process plays a crucial role in the life cycle of an organism, contributing distinctively either to the maintenance of the organism's tissues or to the diversity seen in sexually reproducing populations.