SC- B-2.6: Summarize the characteristics of the cell cycle: interphase;the phases of mitosis, and plant & animal cytokinesis

 in nuclei of eukaryotic cells  made up of: 1. DNA 2. Histones: proteins DNA wraps around

 series of events that cells go through as they grow & divide  What a cell does in the cell cycle:  grow  prepares for division  divides into 2 daughter cells

 time between cell divisions  3 divisions: 1. Gap 1 (G1) 2. S Phase 3. Gap 2 (G2)

 cells do most of their growing  make proteins & organelles  checkpoint  cells destined never to divide again leave cell cycle & enter G0

 synthesis phase  chromosomes duplicated  cells that enter S destined to go thru mitosis

 usually shortest part of interphase  material needed for cell division produced  checkpoint

 4 phases: 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase  each phase may last minutes to days depending on cell type

 longest phase of mitosis  chromosomes become visible (chromatin condenses)  centrioles separate & move to opposite sides of nucleus

 centrioles start to organize mitotic spindle  nuclear envelope & nucleolus disappears

 chromosomes line up across center of cell = metaphase plate  centromere of each chromosome connected to spindle fiber

 centromeres split pulling sister chromatids apart  as soon as split they are called chromosomes  as long as they are moving they are in anaphase

 chromosomes disperse & are no longer visible  2 nuclear envelopes reform & each nuclei starts to form a nucleolus  spindle breaks apart  cleavage furrow becomes visible

 cytoplasm pinches in half  each daughter cell has identical set of duplicate chromosomes

 rigid cell wall cannot “pinch” in half  Cell plate starts to form during telophase  cell wall between 2 daughter cells