 Ch 10 Cell Growth and Division 10-1 Cell Growth 10-2 Cell Division 10-3 Regulating the Cell Cycle

10-1 Cell Growth  The larger a cell becomes, the more demands the cell places on its DNA  In addition, the cell has more trouble moving enough nutrients and wastes across the cell membrane

10-1 Cell Growth  When a cell becomes too large, a growing cell divides forming two “daughter” cells  Before a cell goes through Cell Division, it replicates its DNA so that each daughter cell receives its own genetic library

10-1 Cell Growth  Arts and Crafts Tomorrow-  Now Pg 243 (1-4)  Then Pg 249 “Life Span of Human Cells”  Answer 1-4 in complete sentences

10-2 Cell Division  Mitosis- The division of a Eukaryotic cell (2n) in which the genetic information is identical in both daughter cells (2n)  Before mitosis, chromatids are replicated to become a chromosome, so each daughter can have a set of DNA  Chromosome will be split at the Centromere

10-2 Cell Division  The Cell Cycle is the repeating set of events that make up the life of a cell  The time between cell divisions is called Interphase  Mitosis is a continuous process that is divided into 4 phases: Prophase, Metaphase, Anaphase, and Telophase.  Following Telophase at the end of mitosis is the division of the cytoplasm called Cytokinesis

10-2 Cell Division  Prophase- First step of mitosis in which DNA clusters into chromatids connected at the centromere

10-2 Cell Division  Metaphase- Chromosomes align in the center of the cell where the centromeres align in the middle

10-2 Cell Division  Anaphase- Chromatids of each chromosome separate at the centromere and move to each end of the cell-Separate chromatids=Chromosome

10-2 Cell Division  Telophase- DNA uncoils and a nuclear envelope forms around each set of chromosomes. A new nucleolus forms in each new Nucleus

10-2 Cell Division  The area of the cell membrane that pinches in and eventually seperates the dividing cell into two cells is called the Cleavage furrow  Vesicles formed by the golgi apparatus fuse in the midline of the dividing cell, forming a membrane-bound cell wall called the Cell Plate

Steps of Mitosis Pg 249 (1-6)  Book Questions pg 151 (1,3,4,5,6)

10-3 Regulating the Cell Cycle  Proteins that regulate cell division are called Cyclin  Cell are regulated  Internally-  Make sure cells do not enter mitosis before Chromosomes have been regulated  Make sure chromosomes are attached to the spindle during anaphase  Externally  When you get a cut/wound it tells cells to reproduce  Growth hormones initiate cylin especially during embryonic development

10-3 Regulating the Cell Cycle  A disorder in which some of the body’s own cells lose the ability to control growth is called Cancer  Cancer cells do not respond to the signals that regulate the growth of most cells  Some fail to respond to internal regulators while some fail to respond to external

Questions  Pg 252 (1-5)