1. Cell Division By: Mr. Kauffman

2. Outline Cells Review What is cell division? The Cell Cycle Interphase Mitosis 4 Steps of Mitosis Results of Mitosis Meiosis 8 Steps of Meiosis Results of Meiosis 2 Types of Cell Division

3. Cells Review Cell: smallest part of any living thing that carries out the functions necessary to support life Unicellular organism: living thing made up of 1 cell Multicellular organism: living thing made up of many cells

4. What is cell division? Cell division: a way to produce more cells –U–Usually 1 cell divides to make 2 cells Why is cell division important to multicellular organisms? –I–Its how they grow –R–Replace cells that have died Why is cell division important to unicellular organisms? –I–Its how they reproduce Cancer cell dividing E. Coli cell dividing

5. The Cell Cycle Cell cycle: everything that happens from 1 cell division to the next –2 parts 1. Interphase 2. Mitosis

6. Interphase Interphase: longest part of the cell cycle –The cell prepares to divide It grows in size It copies its DNA

7. Mitosis Mitosis: Part of the cell cycle Mitosis has 4 steps: 1) Prophase 2) Metaphase 3) Anaphase 4) Telophase Cell Division

8. Mitosis Vocabulary Diploid = A cell whose chromosomes that appear in pairs. Haploid = A cell that has only one of each type of chromosome. Parent Cell = In cell reproduction name for the original cell. Daughter Cell = In cell reproduction the name for the cells produced.

9. 4 Steps of Mitosis 1.Prophase –1–1 st step –C–Chromosomes form in nucleus (look like X’s) These are how the DNA is stored in our cells Humans have 46 single chromosomes (23 pairs) –C–Centrioles and spindle fibers begin to form

10. 4 Steps of Mitosis 2.Metaphase –2 nd step –Spindle fibers attach to the chromosomes –Chromosomes are lined up in the middle of the cell

11. 4 Steps of Mitosis 3.Anaphase –3 rd step –Chromosomes are pulled apart –½ of each chromosome goes to each end of the cell

12. 4 Steps of Mitosis 4.Telophase –4 th step –Cytoplasm begins to pinch in at center of cell –Eventually the 1 cell splits to form 2 cells –Chromosomes unravel

13. Results of Mitosis Produces normal, diploid cells in the human body –Ex: skin and muscle 1 cell splits to form 2 cells –The new cells are identical to each other –The new cells are also identical to the original cell

14. Meiosis Meiosis is cell division that produces reproductive cells –Ex: sperm and egg cells Has 2 cell divisions –Basically goes through mitosis 2 times Produces 4 cells –The 4 new cells have ½ the amount of DNA than the original cell had

16. 2 Types of Cell Division in Humans ½ the DNA Comparison to original cell Identical 23 (single) # of chromosomes in cells 46 (single) 4 # of cells produced 2 PMAT (1 and 2) Step names PMAT 8 # of steps 4 Reproductive cells Types of cells produced Normal body cells MeiosisCharacteristicsMitosis