Ms. Napolitano & Mrs. Haas CP Biology

 Interphase: cell growth  G 1, S, & G 2 phases combined  M Phase: cell division  Mitosis – division of the nucleus  Cytokinesis – division of the cytoplasm

 Mitosis = asexual reproduction  Makes identical clones  1 cell = 2 daughter cells Original cell Daughter cells

 Chromosomes – carries genetic information  Made of DNA & proteins  All organisms have a specific number  Fruit flies = 8  Carrots = 18  Humans = 46  Not visible until cell division  Made of two sister chromatids attached at the centromere

 Human body cells (not sex cells) are diploid  One set from mom, one set from dad!  Humans: 2n = 46  23 SETS of chromosomes, 46 total

 4 Stages:  Prophase  Metaphase  Anaphase  Telophase *Don’t forget  Mitosis is followed by cytokinesis!

 Longest phase  Chromosomes become visible  DNA originally chromatin – mass of DNA  Centrioles move to opposite sides of the cell  Spindle fibers form (microtubules)  Nuclear membrane breaks down  Nucleolus disappears

 Chromosomes line up at the center of the cell  Microtubules attach to the centromeres of chromosomes

 Sister chromatids separate  Now become individual chromosomes – confusing, I know!  Move towards opposite poles

 Chromosomes de-condense  Back to chromatin!  Nuclear envelope reforms  Spindle fibers break  Nucleolus reappears

 After mitosis – 2 nuclei in one cell  Cytokinesis divides the cytoplasm  Makes 2 completely different cells  May occur with telophase  Animal cells: membrane drawn in, pinches off  Cleavage furrow formed  Plant cells: cell plate forms between nuclei Cell plate Plant cell Animal cell

=mitosis (This is so cheesy but I think it’s really helpful!)

 2  18  23  46

 Chromosomes  Chromatids  Chromatins

 Centromere  Centriole  Neck  Middle

 Prophase  Metaphase  Anaphase  Telophase

 Prophase  Metaphase  Anaphase  Telophase

 Nuclear membrane disappears  Nucleolus appears  Chromosomes become visible  Centrioles move to opposite poles

 Prophase  Metaphase  Anaphase  Telophase

 True  False