2. Chapter 6: Cell Reproduction Two Types of ReproductionTwo Types of Reproduction a. Sexual – create genetic diversity (offspring not identical to parents) b. Asexual – offspring is identical to parent.

3. Binary Fission Asexual reproductionAsexual reproduction Takes place in prokaryotic cellsTakes place in prokaryotic cells 2 stages:2 stages: –DNA is copied –Cell pinches apart into two identical cells

4. 6-1 chromosomes Eukaryotic cells form 1. DNA copied 2. Chromatids form (exact copies of DNA) Centromere – hooks chromatids together

6. Chromosome number Homologous chromosomes – similar is size, shape, genetic content.Homologous chromosomes – similar is size, shape, genetic content. –Diploid cell – two sets of chromosomes ( one from each parent) –Haploid cell – one set of chromosomes (sex cells)

7. Human Chromosome # Humans – 46 chromosomesHumans – 46 chromosomes –23 from Mom –23 from Dad Sex Chromosomes – determine sexSex Chromosomes – determine sex XX – female, XY - male

8. Somatic cells vs Gamates Somatic cellsSomatic cells body cells (liver, skin) Diploid (46)Diploid (46) Gamate cells – sperm or egg cells Haploid (23) Zygote – two gamates fuse

11. Edwards syndrome Edwards syndrome

12. Down’s Syndrome

13. Chromosome Abnormalities

14. 1. Inversion Inversion – a piece of chromosome breaks off and rejoins in the reverseInversion – a piece of chromosome breaks off and rejoins in the reverse ABCDEF (normal chromosome)ABCDEF (normal chromosome) ACBDEF (inversion)ACBDEF (inversion)

15. 2. Translocation Translocation – a piece of chromosome breaks off and attaches to another chromosomeTranslocation – a piece of chromosome breaks off and attaches to another chromosome

16. Translocation

17. 3. Deletion – Part of a chromosome breaks off and is lost. NormalNormal –1234567 DeletionDeletion –12567 Cri du chat is a rare syndrome (1 in 50,000 live births) caused by a deletion on the short arm of chromosome 5

18. Cri du Chat Karyotype

19. 4. Nondisjuction - One or more chromosomes fail to separateOne or more chromosomes fail to separate –Trisomy – gamate has one extra chromosome –Monosomy – gamate is missing a chromosome

20. Nondisjuction Trisomy http://learn.genet ics.utah.edu/con tent/begin/traits/ predictdisorder/i ndex.htmlhttp://learn.genet ics.utah.edu/con tent/begin/traits/ predictdisorder/i ndex.html

21. Nondisjuction Monosomy Turners Syndrome – female with a missing X chromosome

22. Cell Cycle – cells lifespan http://www.phsuccessnet.com/iText/produc ts/0-13-115075-8/index.html115075

23. Cell Cycle Steps G 1 Phase – rapid growthG 1 Phase – rapid growth S phase – DNA copied (chromatids)S phase – DNA copied (chromatids) G 2 phase – prepare to divideG 2 phase – prepare to divide Mitosis- nucleus dividesMitosis- nucleus divides Cytokinesis- cytoplasm dividesCytokinesis- cytoplasm divides IPMAT cIPMAT c

24. Importance??? Growth Replacement Cancer Regeneration of…

25. Cancer? Unregulated mitosis How does it begin?

26. Mitosis – division of nucleusdivision of nucleus 4 Stages of :4 Stages of : 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase

27. Prophase Chromosomes thickenChromosomes thicken Nuclear membreane breaks downNuclear membreane breaks down Nuclelous issapearsNuclelous issapears Spindle fibers formedSpindle fibers formed Centrioles appearCentrioles appear

28. metaphase Each chromosome lines up midway between polesEach chromosome lines up midway between poles

29. Anaphase Centromeres divideCentromeres divide 2 chromatids separate2 chromatids separate chromosomes pulled to the opposite ends of the cellchromosomes pulled to the opposite ends of the cell

30. Telephase Chromosomes arrive at opposite polesChromosomes arrive at opposite poles Spindle fibers disappearSpindle fibers disappear Nuclear membrane reappearsNuclear membrane reappears Chromosomes uncoil (lighten)Chromosomes uncoil (lighten)

31. Cytokinesis Division of the cytoplasm Result – 2 Identical cells

32. Name stage of mitosis