MITOSIS G1 growth interphase interphase S = synthesis copy DNA Cell Cycle- Cells grow + divide. "cell sex" *Length of time varies. Average is 12-24 hrs 1. Interphase- "Resting phase" .. Liars ! 2. Mitosis- Making of body cells. "somatic" cells dividing. Muscles and nerve 
cells never divide! "My toes itch" 2 identical daughter cells Apoptosis- programmed death of cell. Skin and digestive 
cells divide faster. mitosis checkpoint Why?? 1. Replace 2. Repair 3. Grow too fast = Tumors, cancer too slow = healing problems MITOSIS G2 checkpoint telophase anaphase cytokinesis metaphase G1 growth prophase nucleus divides G2 more growth interphase cell cycle interphase S = synthesis copy DNA G1 checkpoint interphase

MITOSIS 92 92 92 G1, S, G2 46 46 92 46 46 cytokinesis centrioles nucleus nuclear membrane nucleolus cytoplasm 92 92 92 centrioles centrioles move to the poles nuclear membrane /nucleolus disappears chromatin turns into chromosomes G1, S, G2 spindle fibers 46 46 cytokinesis 92 46 46 chromosomes line up on the equator chromosomes are pulled to the poles centrioles disappear nuclear membrane/nucleolus reappear chromosomes go back to chromatin 2 identical daughter cells made

92 46 46 92 46 46 92 46 46 46 46 cytokinesis metaphase II 23 23 MEIOSIS- making of gametes/sex cells- AKA reduction division cell membrane prophase II nucleolus 92 nuclear membrane interphase 46 46 centrioles chromatin spindle fibers 92 46 46 chromosomes prophase I crossing over tetrad=4 metaphase II 23 23 92 metaphase I anaphase II 23 23 anaphase I 46 46 telophase II 23 23 telophase I 46 46 cytokinesis

spermatogenesis oogenesis 92 92 23 23 23 23 polar bodies- they die egg