1. Ch. 9.1: Cell Reproduction Objectives: 1.Describe how cell reproduction contributes to repair and to growth. 2.Contrast asexual and sexual reproduction. Vocab.: asexual reproduction; sexual reproduction

2. Why do cells need to reproduce? 1.Repair and replacement of dead or damaged cells. 2.Growth = increase in size

3. Asexual Reproduction  Single cell duplicates its genetic material and then splits into 2 genetically identical cells.  1 parent  Parent & offspring are identical  Most single celled organisms  Many multicellular have option (plants, marine organisms)

4. Sexual Reproduction  Genetic material from 2 parent combines.  Offspring genetically different fr. parents  Involve sperm & egg  Meiosis involved

5. Ch. 9.2: The Cell Cycle Objectives: 1.Describe the structure of a chromosome. 2.Name the stages of the cell cycle and explain what happens during each stage. Vocab.: chromatin, chromosome, sister chromatid, centromere, cell cycle, interphase, mitotic phase, mitosis, cytokinesis

6. 9.2: Cell Cycle

7. 9.2: Chromosomes & Cell Division Chromatin = long fibers of DNA + proteins Chromatin --> Chromosomes before cell divides Chromosomes: Condensed threads of genetic material formed fr. Chromatin as a cell prepares to divide. Humans: 46 chromosomes (23 pair)

8. 9.2: Chromosomes & Cell Division Sister Chromatids: 1 pair of identitical chromosomes created before a cell divides. Centromeres: Where 2 sister chromatids are joined.

9. 9.2: Cell Cycle Interphase: When cell is not dividing. Carrying out metabolic fxns, grow, etc. ~ 90% of cell life S: DNA duplicated

10. 9.2: Mitosis Mitosis Stage of the Cell cycle where cell is DIVIDING. (M phase) Mitosis: Nucleus & duplicated chromosomes divide. Cytokinesis: Cytoplasm divides into 2.

11. Ch. 9.3: Mitosis Division of somatic cells (body) Somatic Cell Daughter Cells

12. Chromosomes Strands of DNA Each human has 23 pair (diploid or 2n) –One from your mother –One from your father

13. Chromosome One from Mom One from Dad Sister chromatids DNA molecule with attached proteins Look at figure 8.2

14. Mitosis First you duplicate DNA Why? –You have 2 pairs of 23 chromosomes –If cell splits, you will only have 1 pair –Duplicate DNA, cell splits, still have 2 pair Sex chromosomes- X and Y: XX is female in humans, XY is male

15. Interphase Prior & After Mitosis G1 period –90% of cell life spent here –Cell goes about it’s business S period –DNA is duplicated G2 period –Cell prepares to divide Cannot see DNA- uncoiled as chromatin

16. 1. Prophase DNA becomes visible as chromosomes Nuclear membrane dissolves Centrioles migrate to opposite poles Spindle fibers form Easy to remember- Prophase- proceeding into mitosis

17. 2. Metaphase Spindle fibers attach to centromeres Chromosomes line up at midline of the cell Easy to remember- metaphase, DNA at middle Spindle Equator Pole

18. 3. Anaphase Spindle fibers pull apart centromeres One chromatid goes to each centriole (they look like V’s) Easy to remember- anaphase, apart they go

19. 4. Telophase Chromatids reach centrioles Mitosis ends when new nuclear membranes form Some evidence of cell dividing Easy to remember- telophase, terminal phase

20. Last part- Cytoplasmic division Technically not in mitosis –Animal cell- pinching of cell membrane- cleavage –Plant cell- formation of new cell wall- cell plate –DNA becomes non-visible, back to chromatin Daughter cells enter G1 period of interphase

21. Cancer Uncontrollable mitosis (no G1) –Cells cease to do what they are supposed to be doing in favor of dividing. Pancreatic cancer- no longer in interphase Cease production of insulin Incomplete digestion of food Diabetes, abdominal pain, weight loss Cancer does not “poison” your body…

22. Henrietta Lacks 1951, a poor 31 Year old African American mother of 4 was dying of cervical cancer @ Johns Hopkins Hospital –Dr. George Gey- sampled some of the cancerous cells, found they could live indefinitely and multiply outside the body –She died 6 months later, but cells live on HeLa cells –Used to study many different diseases –Cure for Polio