* Mitosis: Creates two identical daughter cells with the same number of chromosomes as the parent cell. This is essential for growth and repair.
* Meiosis: Creates four daughter cells, each with half the number of chromosomes as the parent cell. This is essential for sexual reproduction, and the key is that these daughter cells are genetically unique.
How does meiosis introduce genetic diversity?
1. Crossing Over: During prophase I, homologous chromosomes (one from each parent) exchange segments of DNA. This shuffling of genetic material creates new combinations of alleles.
2. Independent Assortment: During metaphase I, homologous chromosomes align randomly at the metaphase plate. This means that the daughter cells receive a random mix of chromosomes from each parent, further increasing genetic variation.
Why is genetic diversity important?
* Adaptation: Genetic variation within a population increases the likelihood that some individuals will have traits that allow them to survive and reproduce in changing environments.
* Evolution: Genetic diversity is the raw material for evolution. Over generations, natural selection acts on this variation, favoring traits that increase survival and reproduction, leading to the evolution of new species.
In summary, mitosis produces identical copies, while meiosis introduces genetic variation, which is crucial for sexual reproduction and the long-term survival of species.
