Mitosis and meiosis are two types of cell division processes, but they serve different purposes and have distinct characteristics. Here are the key differences between the two:
-
Purpose:
- Mitosis: It is primarily for growth, tissue repair, and asexual reproduction. It produces identical daughter cells for the purpose of replacing dead or damaged cells.
- Meiosis: It is specialized for sexual reproduction and produces gametes (sperm and eggs) with half the genetic material of the parent cell, leading to genetic diversity in offspring.
-
Number of Divisions:
- Mitosis: Involves a single division resulting in two daughter cells.
- Meiosis: Involves two consecutive divisions (Meiosis I and Meiosis II), resulting in four daughter cells.
-
Genetic Composition of Daughter Cells:
- Mitosis: Daughter cells are genetically identical to the parent cell and each other (clonal).
- Meiosis: Daughter cells are genetically diverse due to recombination and independent assortment, resulting in cells that are haploid (containing one set of chromosomes).
-
Chromosome Number:
- Mitosis: Maintains the same chromosome number as the parent cell (diploid to diploid).
- Meiosis: Reduces the chromosome number by half (diploid to haploid).
-
Stages:
- Mitosis: Consists of prophase, metaphase, anaphase, and telophase, followed by cytokinesis.
- Meiosis: Consists of two rounds of division, each with its own set of phases (Meiosis I includes prophase I, metaphase I, anaphase I, telophase I; Meiosis II includes prophase II, metaphase II, anaphase II, telophase II).
-
Crossing Over:
- Mitosis: No crossing over occurs. Chromatids remain identical.
- Meiosis: Crossing over can occur during prophase I, where genetic material is exchanged between homologous chromosomes, increasing genetic variation.
-
Resulting Cells:
- Mitosis: Results in two diploid somatic cells.
- Meiosis: Results in four haploid gametes.
These differences highlight the unique roles of mitosis and meiosis in biology, particularly in the context of growth, repair, and reproduction.