Mitosis
MITOSIS Every second, millions of cells in your body are dividing. Some divisions help you grow or heal, while others make the cells needed for reproduction. Let’s break it down. Chromosomes Basics Chromosomes = DNA wrapped around histones, keeping it neat and organized Sister chromatids = identical copies of a chromosome after DNA replication Homologous chromosomes = one from mom, one from dad; same genes but possibly different versions Karyotypes A picture of all your chromosomes, arranged by size and shape 22 pairs of autosomes + 1 pair of sex chromosomes (XX = female, XY = male) Diploid vs. Haploid Diploid (2n) = two sets of chromosomes → body cells Haploid (n) = one set of chromosomes → gametes (sperm/egg) Possible gamete combinations = 2ⁿ (for humans, over 8 million!) The Cell Cycle and Mitosis Interphase: G1 (cell grows), S (DNA copied), G2 (error check) Prophase: chromosomes condense, spindle forms, nucleus breaks down Metaphase: chromosomes l...