Chapter 10 Cell Growth & Division Why do cells not get super sized like an Ostrich Egg? Information Crisis or DNA overload Volume - surface area increases more slowly Calculate the surface area And volume. 3 2 1 3 1 2
Cell Division - General 1. What is a daughter cell? 2. Is this sexual or asexual - fun or no fun? 3. Cell division occurs in what two stages?
Cell Division - Chromosomes Chromosome are made of? What do chromosomes do? Do all creatures have the same number? How Many do you have?
Cell Division - Interphase • G1 Phase • cells grow • synthesize additional proteins • Synthesize additional organelles 2. S Phase • Replicates (duplicate copies) chromosomes 3. G2 Phase • synthesize additional proteins • Synthesize additional organelles
Cell Division - Mitosis • PMAT • Prophase • Longest Stage • Chromosomes Condense • Centrioles move to poles • Nuclear Envelope Disappears • Spindle fibers attach to centromere • Nucleolus Disappears 2. Metaphase • Centromere becomes connected to the poles • Chromosomes line up at equator
Cell Division - Mitosis • PMAT • 3. Anaphase • Centromere splits separating sister chromatids / each is now considered an individual chromosome 4. Telophase • Chromosomes uncondense • Nuclear envelope (membrane) reforms • Spindle fibers break up • Nucleolus reforms
Cell Division - Cytokinesis By definition this is the division of the cytoplasm In animal cells the membrane pinches inward In plant a cell wall forms from cell plates
Controls of Cell Division • Why would cells divide? • Why would they stop growing? • Internal (based on what is happening inside the cell) • Cyclins • External regulation • Surface Proteins
Uncontrolled Cell Growth Uncontrolled growth of the bodies cells is known as______? Malignant Vs. Benign Metastasizes
Stem Cells & Controversy Adult Stem Cells 1. Difficult to isolate and limited differentiation 2. If differentiation of adult stem cells can be controlled, these cells may be used for creating transplants. Heart Stem Cells: http://www.cnn.com/2011/11/14/health/stem-cells-heart-damage-reverse/index.html?hpt=hp_c1 Embryonic Stem Cells 1. First cell growth of a fertilized egg 2. Most come from in vitro sources 3. Greater differentiation
Stem Cells All stem cells are difficult to direct towards intended goal Therapeutic Cloning - nucleus of a cell (skin) inserted into an egg whose nucleus has been removed