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# Meiosis Meiosis is a type of cell division that produces gametes (sex cells). **Prophase 1:** * Homologous chromosomes (chromosomes that have the same structure, size, and genes) pair up. * Crossing over can occur, exchanging genetic material between homologous chromosomes. * The nuclear membra...

# Meiosis Meiosis is a type of cell division that produces gametes (sex cells). **Prophase 1:** * Homologous chromosomes (chromosomes that have the same structure, size, and genes) pair up. * Crossing over can occur, exchanging genetic material between homologous chromosomes. * The nuclear membrane dissolves. * Spindle fibers form. **Metaphase 1:** * Homologous chromosome pairs line up in the middle of the cell. * Spindle fibers attach to the chromosomes. **Anaphase 1:** * Homologous chromosomes are pulled apart by the spindle fibers. **Telophase 1:** * Chromosomes reach opposite poles of the cell. * Cytokinesis (division of the cytoplasm) occurs, creating two haploid (half the number of chromosomes as the parent cell) daughter cells. **Meiosis 2:** * Prophase 2: Spindle fibers form in each of the two haploid daughter cells. * Metaphase 2: Sister chromatids line up in the middle of each cell. * Anaphase 2: Sister chromatids are pulled apart by the spindle fibers. * Telophase 2: Four haploid daughter cells are produced, each with a single chromosome set. **Functions of Meiosis:** * **Sexual reproduction:** Meiosis produces gametes (sperm and egg cells). * **Genetic variation:** Crossing over during prophase 1 and the random assortment of chromosomes during metaphase 1 create genetic diversity in the offspring. * **Maintaining chromosome number:** In sexual reproduction, the fusion of two haploid gametes produces a diploid zygote with the correct number of chromosomes for the species. **Differences between male and female meiosis:** * **Males:** Produces four genetically distinct sperm. * **Females:** Produces one large egg cell and three smaller polar bodies, which are usually reabsorbed. **Significance:** * Meiosis is crucial for the survival and diversity of sexually reproducing organisms. * Chromosome number is maintained across generations. * Genetic variation drives evolution through the combinations of parental genes in offspring.