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Mitosis. Do-Now: begin reading p.244 and 245. How do cells replicate?. In asexually reproducing organisms, all the genes come from a single parent. Because the genes come from one parent, the offspring is genetically identical. 1 cell 2 cells. How do cells replicate?.
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Mitosis Do-Now: begin reading p.244 and 245
How do cells replicate? • In asexually reproducing organisms, all the genes come from a single parent. • Because the genes come from one parent, the offspring is genetically identical. • 1 cell 2 cells
How do cells replicate? • All cells in the body except sex cells reproduce by mitotic cell division. • When cells grow to a certain size, they must either divide or die. • The daughter cells must have the same number and type of chromosomes as the parent cell.
Cell Life Span • Cell lining of esophagus 2-3 days • Red Blood Cells (cannot divide) <120 days • Cardiac Muscle(cannot divide) long lived • Cell lining of large intestine 6 days • P.249 in home textbook.
Chromosomes • Chromosomes are long threadlike structures located in the nucleus of the cell. • They contain hereditary information organized as genes. • Genes control cell activities and may be copied and passed on to the next generation.
Why are chromosomes important? • Chromosomes contain genes. • Genes are the blueprint for the cells. • A single chromosome contains thousands of genes that code for a protein which determines how a person’s body develops and functions. • Humans have 46 chromosomes. In other words: 23 pairs. The last pair determines if you are a boy or girl.
Phases of the Cell Cycle • Interphase(G1,S,G2) • G1 phase- intense growth and biochemical activity • S phase- replication of DNA(making exact copies of the DNA) • G2 phase- cell continues to grow and prepares for mitosis
The M(mitosis) phase • PMATC(prophase,metaphase,anaphase,telophase,cytokinesis) • Prophase double stranded chromosomes become visible. Nuclear membrane disappears. Spindle forms.
Metaphase: centromeres become attached to spindle. All chromosomes line up in the middle. • Anaphase: chromatids separate. The chromosomes move apart toward the opposite poles. • Telophase: nuclear membrane forms around each set of chromosomes • Cytokinesis: cytoplasm completely splits into two cells.
http://www.cosmeo.com/videoTitle.cfm?&nodeid=&guidAssetId=BF72CEA5-C2B1-4AB0-AE17-1A6BC2B97621http://www.cosmeo.com/videoTitle.cfm?&nodeid=&guidAssetId=BF72CEA5-C2B1-4AB0-AE17-1A6BC2B97621 • http://biologyinmotion.com/cell_division/ • http://www.cellsalive.com/meiosis.htm • http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120073/bio14.swf::Mitosis and Cytokinesis::/sites/dl/free/0072437316/120073/bio14.swf::Mitosis and Cytokinesis