Cell Growth and Reproduction

1. Chapter 3 Pg. 98-104 Cell Growth and Reproduction

2. The Cell’s Life Cycle • There are a series of changes a cell goes through during its lifespan (much like us!!), it is divided into two main segments: Interphaseand cell division/mitotic phase

3. Two Stages of Cell Division • Interphase • It is referred to as the “resting phase” • However, this is a misnomer in the since it is only “resting” from actual division • It should be called a growth or metabolic phase • Divided into three subphases: G1, S, G2 • Mitotic Phase • Essential for body growth and tissue repair • Two distinct events: mitosis and cytokinesis

4. Interphase’s Subphases • Prepares the cell for the next division (mitosis) • In all three subphases the cell grows by producing proteins AND organelles (chromatin is ONLY reproduced during the S phase) • During the G1 the cell grows very rapidly-may last from several minutes to hours in cells that reproduce frequently or days to even years in those that reproduce very slow

5. Interphase’s Subphases • During the S phase DNA replicates, if something goes wrong in the phase, mitosis will NOT be able to occur • The G2 is the briefest out the three and this is where enzymes and other proteins are created and sent to their proper locations

7. Cell Division • Creates two daughter cells from one mother cell • Has four phases: Prophase, Metaphase, Anaphase, Telophase • Is a continuous process that typically lasts about an hour or less • Division of cytoplasm • Begins during late anaphase and is completed after telophase • The cell membrane is drawn inward to form a cleavage furrow Mitosis Cytokinesis