10.2 Eukaryotic Cell Cycle Cell cycle--repeating phases of : –Growth (Interphase) –DNA replication (Interphase) –preparation for cell division (Interphase) –division of the nucleus and cytoplasm (cell division—mitosis & cytokinesis)
Interphase G 1 : cell grows to mature size, makes more organelles S: chromosomes replicate G 2 : cell continues to grow and prepare to divide; cell forms specialized structures that help the cell divide (ex. microtubules)
2 Stages of Cell Division: 1.Mitosis: the process in which a cell’s nucleus divides into 2 identical daughter nuclei. *Begins after interphase and ends before cytokinesis. *PMAT (4 phases) 2.Cytokinesis: cytoplasm division (and organelles) *Cell physically splits into 2
MITOSIS — 4 phases (PMAT): 1. PROPHASE chromosomes condense (coil up and become visible under a microscope). Centrosome helps to assemble spindle fibers. a pair of centrioles migrate to each pole of the cell (animal cells only). nuclear envelope and nucleolus break down (disappear).
4. TELOPHASE 2 daughter nuclei are formed reverse of prophase: nuclear envelopes form around each set of chromosomes; chromosomes uncoil to form a loose mass of chromatin; spindle fibers break down (disappear).
CYTOKINESIS animal cell…cell membrane grows into the center of the cell at the center of the parent cell and divides it into 2 daughter cells of equal size; called a cleavage furrow plant cells…form a cell plate (from the parent cell wall).