1. Intro to Cell Division Topics: DNA Anatomy of a Chromosome Why does a cell divide? The Cell Cycle

2. DNA & Genetics (Do not write slide ) Life as a cell… –Cells are born, they grow and then they… Die, or… Reproduce How?

3. DNA DNA is the genetic code of an organism DNA is carried and passed on by chromosomes Chromosomes contain MANY different genes –Different genes are what give you your: Sex Hair, eye and skin colour Height Everything that you were born with. Genes are coded for different traits by bases

4. Anatomy of a Chromosome Chromosomes hold the DNA in the nucleus Chromosome Supercoils Coils Nucleosome Histones DNA double helix

5. Anatomy of Chromosome cont… Cells must pass on their DNA (using the chromosomes) to their daughter cells

6. Anatomy of a Chromosome Sister Chromatids: Identical strands of a chromosome with identical DNA Centromere: node where the sister chromatids attach

7. Cell Cycle (do not write) Cells Cycle: The life of a cell: Cell grows, Prepares for division, Divides to daughter cells, Cycle begins again M phase G 2 phase S phase G 1 phase

8. 2 Main Events of the Cell Cycle (do not write) Interphase: Cell grows & prepares for Mitosis (see previous slide for diagram) –G1: Growth –Synthesis (S) = Chromosomes replicate –G2 = Organelles & Molecules for mitosis are produced Mitosis: Cell divides to form two genetically identical cells

9. Questions???