1. Welcome to Class What is probability? What is the probability of pulling an Ace out of a deck of cards?

2. Agenda Finish probability Mitosis and Meiosis

3. Chromosomes Chromosome – cell structure that contains DNA (Bio A) Gene – on DNA, controls protein synthesis Homologous chromosomes - Chromosomes that make a pair – 1 from each parent Humans have 46 chromosomes

4. How do we maintain 46 Chromosomes? Produce gametes – sex cells that have half the number of chromosomes Humans have 23 chromosomes per gamete Cell with ½ the number of regular chromosomes (n) is called haploid Cell with all chromosome (2n) is called diploid

5. 6 Stages of Mitosis Interphase – DNA replicates Prophase – Chromosomes condense, spindles appear, nuclear membrane disappears Metaphase – chromosomes attach to spindles, align in center of cell Anaphase – chromosomes move to opposite ends of cells Telophase – nuclear envelope reappears, chromosome decondense Cytokinesis – Cells divide into two cells

7. Meiosis I Interphase – Chromosomes replicate – Similar to Mitosis! Prophase I – homologous chromosomes pair 1 from mom, 1 from dad – Nuclear envelope breaks down, spindles form – Crossing over!

8. Meiosis I Metaphase I – Homologous chromosomes line up at center Anaphase I – Homologous pairs move to opposite sides of cell Telophase I – Chromosomes uncoil – Cell divides

10. Meiosis II Prophase II - no DNA replication!!! – Chromosomes condense – Spindle fibers appear Metaphase II – Chromosomes line up at center Anaphase II – Chromosomes split and move to opposite sides Telophase II – Nuclei form around chromosomes – Cells divide

12. MeiosisMitosis Chromosome Number: Reduced by half (homologous pairs separate) Remains the same Pairing of Homologues:YesNo Function:sexual reproduction Cellular (asexual) Reproduction (cell division during which the cell nucleus divides); general growth and repair of the body Number of Divisions: 2 nuclear and 2 cytoplasmic divisions 1 division of the nucleus and 1 Cytokinesis Number of Cells produced:42 Creates: Sex cells only: Female egg cells or Male sperm cells Makes everything other than sex cells (Somatic Cells) Occurrence of Crossing Over: YesNo Produces:four haploid daughter cellstwo diploid daughter cells Genetically:differentidentical

13. MeiosisMitosis Two cell divisions Centrioles appear Half the original chromosomes Homologous Chromosomes pair up Spindle fibers form Cytokinesis Four daughter cells 46 Chromosomes at end X X X X X X X X X X X

14. http://biologycorner.com/worksheets/meiosis _internet.html http://biologycorner.com/worksheets/meiosis _internet.html

15. Welcome to Class Define diploid and haploid.

16. Agenda Review mitosis and meiosis Compare and contrast mitosis and meiosis CH. 10 Study guide

17. Cytokinesis

20. MeiosisMitosis Chromosome Number: Reduced by half (homologous pairs separate) Remains the same Pairing of Homologues:YesNo Function:sexual reproduction Cellular (asexual) Reproduction (cell division during which the cell nucleus divides); general growth and repair of the body Number of Divisions:21 Number of Cells produced:42 Creates: Sex cells (GAMETES): Female egg cells or Male sperm cells Makes “normal” cells(Somatic Cells) Occurrence of Crossing Over: YesNo Produces:four haploid daughter cellstwo diploid daughter cells Genetically:differentidentical

21. MeiosisMitosis Two cell divisions Centrioles appear Half the original chromosomes Homologous Chromosomes pair up Spindle fibers form Cytokinesis Four daughter cells 46 Chromosomes at end X X X X X X X X X X X

22. Welcome to Class What are three main differences between mitosis and meiosis?

23. Agenda Quiz Finish Study guide Traits survey Mendel

24. Online Bio Books Access Code: CCF2754895 Glencoe.com

25. Welcome to Class What is a trait?

26. Agenda Mitosis/Meiosis Review – Drawing Traits survey Mendel

27. Mitosis/Meiosis Review 1. Number of Cells – Mitosis creates 2 identical cells – Meiosis creates 4 individual cells 2. Number of chromosomes – Mitosis creates cells with 46 chromosomes (2n – diploid) – Meiosis creates cells with 23 chromosomes (n – haploid) 3. Locations – Mitosis – somatic (“normal”) cells – Meiosis – gametes (sex) cells

28. Drawing Mitosis and Meiosis

29. 1. Interphase 2. Prophase 3. Metaphase4. Anaphase 5. Telophase/Cytokinesis

30. 1. Prophase I 2. Metaphase I 3. Anaphase I 4. Telophase/Cytokinesis I

31. 1.Prophase II Cells from Meiosis I 2. Metaphase II 3. Anaphase II 4. Telophase II /Cytokinesis II

32. Importance of Meiosis Genetic Variation

33. Sexual vs. Asexual Reproduction Asexual Organisms inherit all chromosomes from single parent Genetically identical Sexual Chromosomes from 2 parents Genetic variation