Chapter 8 Mitosis (asexual cell reproduction) Chromosomes (during cell division, condensed) Chromatin (between cell divisions, dispersed) Chromatid (a single copy of a chromosome) Mother cell 1 chromatid/chromosome DNA replicationī 2chromatids/chromosome Mitosisī chromatids split Daughter cells have 1 chromatid/chromosome And so the cycle goes… Interphase: replication of DNA Prophase: chromatin condenses to chromosomes Prometaphase: microtubules tug of war on chromosomes Metaphase: chromosomes line up at metaphase plate Anaphase: chromatids separate Telophase: daughter nuclei form Cytokinesis: cytoplasms separate Cell division must be regulated A failure of regulation is what we call cancer Mutagens are potentially carcinogenic Chapter 9 Meiosis Sexual cell reproduction Haploid=1N Diploid=2N Homologous chromosomes (pairs of chromosomes: 23 pairs in a human 223 unique gametes for each person due to independent assortment Three sources of genetic variation in sexual reproduction 1) independent assortment 2) crossing over 3) different sperm and different egg combination some organisms, the haploid is the dominant part of life cycle (e.g. fungi, mosses)