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Reproduction . Ms. Lavoie Living Environment. 2/4/2012 Aim : Why do cells have to reproduce?. Do now : Describe the three statements of the cell theory. HW : do now quiz on these notes tom Vocab due fri -test grade. The Cell Theory All living things are made of cells.
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Reproduction Ms. Lavoie Living Environment
2/4/2012Aim: Why do cells have to reproduce? • Do now: Describe the three statements of the cell theory. • HW: do now quiz on these notes tom • Vocab due fri-test grade
The Cell Theory • All living things are made of cells. • Cells are the basic unit of structure and function (they carry out life functions) • All cells come from pre-existing cells • Video clip
Why do cells have to reproduce? • When you were younger did you ever have a bad fall and scratch your knee or any other part of your body? Yes • Can you see it now? No • How did the healing take place? Mitosis • Survival of the species • To grow
Cell Division • Mitosis is nuclear division plus cytokinesis (splitting of cytoplasm) • It produces 2 identical daughter cells • Mitosis is classified as ASEXUAL b/c it produces “clones” of the parent cell
Replication • The genetic material (DNA): Genetic Material inacell is found in the chromosomes. • These chromosomes must be doubled to form 2 chromatids. • When the cells divide 1 chromatid goes to each new cell.
Why is it important that the sister chromatids be identical? CHROMATID CENTROMERE Sister Chromatids
Stages of Mitosis Animation courtesy of Tom Diab. Used with permission. http://www.geocities.com/Athens/Olympus/5297/ • IPMAT (Interesting People Meet And Talk)
Interphase (I) • Aka Resting phase (16-20 hrs) • Cell is growing • Chromosomes are replicating • Centrioles in animal cells are replicating
Prophase (P) Start of Mitosis • Chromatids connected by centromere are more visible • Nuclear membrane starts to disappear • Centrioles move to opposite poles • Spindlefibers appear and attach
Metaphase (M) • Chromosomes (Chromatid pairs) line up in the middle of the cell • Attach to spindlefibers • Centromere divides and chromatids are separated
Anaphase (A) • Chromosomes separate and move to opposite ends of the cell.
Telophase (T) • Nuclear Membranes form • Pinching in of animal cell to form two cells
Animal vs. Plant • Cytokinesis = splitting of the cytoplasm • Animals • cytokinesis = pinching in of cell membrane • Centrioles present • Plants • Cytokinesis = formation of a cell plate • No centrioles present
Review • Mitosis = nuclear division • Cytokinesis = cytoplasm division • Production of 2 identical daughter cells • Animals vs. plants
Video • http://www.hybridmedicalanimation.com/anim_mitosis_wmVideo.html • http://highered.mcgraw-hill.com/sites/0073031216/student_view0/exercise13/mitosis_movie.html
Exit pass • Put plates in order