1. 1.Enter the classroom silently and find your seat. 2.Turn in homework, copy down hw in planner 1.Vocab Quiz Mon/Tues 10 min AGENDA DO NOW: Begin reading (103 - 108) in essentials book FRQ! Objective 1: SWBAT Differentiate between sexual and asexual reproduction. Objective 2: SWBAT Summarize the stages and significance of meiosis. 10/13/15 Statement of Inquiry: How do sex cells multiply?

2. Objective of the day Objective 1: SWBAT Differentiate between sexual and asexual reproduction. Objective 2: SWBAT Summarize the stages and significance of meiosis.

3. MEIOSIS Creating gametes (sex cells)

4. Chromosome Number A human body cell has 46 chromosomes 23 from dad and 23 from mom These sets of chromosomes are homologous, meaning that each chromosome that came from dad has a corresponding chromosome from mom.

5. Diploid and Haploid A cell that contains both sets of homologous chromosomes is said to be diploid. Diploid= “ two sets”, 2N, or 2N=46 A cell that only contains 1 set of chromosomes is said to be haploid. Haploid= “one set”, N, or N=23

6. Statement of Inquiry/IB Trait STATEMENT OF INQUIRY: Humans use their understanding of scientific principles to look for patterns and evidence using models that can change the way we understand our current world. IB TRAIT: KNOWLEDGEABLE, COMMUNICATORS and INQUIRERS

7. Homework Write definitions for: NOTECARDS! Gametogenesis sperm egg polar body somatic cell gamete homologous chromosome autosome sex chromosome sexual reproduction fertilization diploid haploid meiosis

8. 8 Types of Cell Reproduction Asexual reproduction involves a single cell dividing to make 2 new, identical daughter cells Asexual reproduction involves a single cell dividing to make 2 new, identical daughter cells Mitosis & binary fission are examples of asexual reproduction Mitosis & binary fission are examples of asexual reproduction Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is NOT identical to the original cells Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is NOT identical to the original cells Meiosis is an example Meiosis is an example

9. 9 Meiosis Formation of Gametes (Eggs & Sperm)

10. 10 Facts About Meiosis Preceded by interphase which includes chromosome replication Preceded by interphase which includes chromosome replication Two meiotic divisions --- Meiosis I and Meiosis II Two meiotic divisions --- Meiosis I and Meiosis II Called Reduction- division Called Reduction- division Original cell is diploid (2n) Original cell is diploid (2n) Four daughter cells produced that are monoploid (1n) Four daughter cells produced that are monoploid (1n)

11. 11 Facts About Meiosis Daughter cells contain half the number of chromosomes as the original cell Daughter cells contain half the number of chromosomes as the original cell Produces gametes (eggs & sperm) Produces gametes (eggs & sperm) Occurs in the testes in males (Spermatogenesis) Occurs in the testes in males (Spermatogenesis) Occurs in the ovaries in females (Oogenesis) Occurs in the ovaries in females (Oogenesis)

12. Phases of Meiosis Occurs in 2 divisions- meiosis I and meiosis II In the end one diploid cell will become 4 haploid cells

13. Crossing Over occurs in Meiosis I 1. Homologous chromosomes form a tetrad 2. Chromatids cross over one another 3. The crossed sections of chromatids are exchanged 4. This produces a new combination of genes which contributes to diversity within a population.

14. Gamete Formation occurs in Meiosis II Meiosis I results in 2 haploid daughter cells Meiosis II results in 4 haploid daughter cells The haploid gamete in males is sperm The haploid gamete in females is the egg

15. 15 Fertilization – “Putting it all together” 1n =3 2n = 6

16. 16 Meiosis: Two Part Cell Division Homologsseparate Sisterchromatidsseparate Diploid Meiosis I Meiosis II Diploid Haploid copyright cmassengale

17. 17 Meiosis I: Reduction Division Nucleus Spindlefibers Nuclearenvelope Early Prophase I (Chromosome number doubled) Late Prophase I Metaphase I Anaphase I Telophase I (diploid) copyright cmassengale

18. 18 Prophase I Early prophase Homologs pair. Homologs pair. Crossing over occurs Crossing over occurs. Late prophase Chromosomes condense. Chromosomes condense. Spindle forms. Spindle forms. Nuclear envelope fragments. Nuclear envelope fragments. copyright cmassengale

19. 19 Tetrads Form in Prophase I Homologous chromosomes (each with sister chromatids) Homologous chromosomes (each with sister chromatids) Join to form a TETRAD Called Synapsis copyright cmassengale

20. 20 Crossing-Over Homologous chromosomes in a tetrad cross over each other Homologous chromosomes in a tetrad cross over each other Pieces of chromosomes or genes are exchanged Pieces of chromosomes or genes are exchanged Produces Genetic recombination in the offspring Produces Genetic recombination in the offspring copyright cmassengale

21. 21 Metaphase I Homologous pairs of chromosomes align along the equator of the cell copyright cmassengale

22. 22 Anaphase I Homologs separate and move to opposite poles. Sister chromatids remain attached at their centromeres attached at their centromeres. copyright cmassengale

23. 23 Telophase I Nuclear envelopes reassemble. Spindle disappears. Cytokinesis divides cell into two. copyright cmassengale

24. BRAIN BREAK (7mins) Class Bingo: Fill in your randomly with numbers 1- 25. EXAMPLE ABCD 131615 49522 1711612 252713

25. 25 Prophase II Nuclear envelope fragments. Spindle forms. copyright cmassengale

26. 26 Metaphase II Chromosomes align along equator of cell. copyright cmassengale

27. 27 Anaphase II Sister chromatids separate and move to opposite poles Sister chromatids separate and move to opposite poles. Equator Pole copyright cmassengale

28. 28 Telophase II Nuclear envelope assembles. Chromosomes decondense. Spindle disappears. Cytokinesis divides cell into two. copyright cmassengale

29. 29 Results of Meiosis Gametes (egg & sperm) form Four haploid cells with one copy of each chromosome One allele of each gene Different combinations of alleles for different genes along the chromosome copyright cmassengale

30. Guided practice In your pairs complete the mitosis v meiosis GP. You will have 10 minutes to work. 10 min

31. 31 Gametogenesis Oogenesis or Spermatogenesis copyright cmassengale

32. 32 Spermatogenesis Occurs in the testes Occurs in the testes Two divisions produce 4 spermatids Two divisions produce 4 spermatids Spermatids mature into sperm Spermatids mature into sperm Men produce about 250,000,000 sperm per day Men produce about 250,000,000 sperm per day copyright cmassengale

33. 33 Spermatogenesis in the Testes Spermatid copyright cmassengale

34. 34 Oogenesis Occurs in the ovaries Occurs in the ovaries Two divisions produce 3 polar bodies that die and 1 egg Two divisions produce 3 polar bodies that die and 1 egg Polar bodies die because of unequal division of cytoplasm Polar bodies die because of unequal division of cytoplasm Immature egg called oocyte Immature egg called oocyte Starting at puberty, one oocyte matures into an ovum (egg) every 28 days Starting at puberty, one oocyte matures into an ovum (egg) every 28 days copyright cmassengale

35. 35 Oogenesis in the Ovaries copyright cmassengale

36. Comparing Mitosis and Meiosis Mitosis Results in 2 identical diploid cells Involves asexual reproduction 1 division Meiosis Results in 4 genetically different haploid cells Involves sexual reproduction 2 divisions CLICK FOR ANIMATED COMPARISON

37. 37 MitosisMeiosis Number of divisions 12 Number of daughter cells 24 Genetically identical? YesNo Chromosome # Same as parent Half of parent Where Somatic cells Germ cells When Throughout life At sexual maturity Role Growth and repair Sexual reproduction Comparison of Divisions copyright cmassengale

38. CFU 1. Do Mitosis and meiosis both result in diploid cells? 2. What type of body cell does the process of meiosis form? 3 min

39. Possible Answer 1. Do Mitosis and meiosis both result in diploid cells? (No; meiosis produces haploid cells and mitosis produces 2 diploid cells.) 2. What type of body cell does the process of meiosis form? (reproductive cells)

40. Independent Practice Complete the Independent Practice #1 worksheet in your guided notes. Voice Level 0 15 min

41. Discuss what you learned today in class. Turn and Talk 2 min