1. MEIOSIS 11-4 Making gametes… http://waynesword.palomar.edu/lmexer2a.htm

2. Interest Graber 1. How many chromosomes would a sperm or an egg contain if either one resulted from the process of mitosis? 2. If a sperm containing 46 chromosomes fused with an egg containing 46 chromosomes, how many chromosomes would the resulting fertilized egg contain? Do you think this would create any problems in the developing embryo? 3. In order to produce a fertilized egg with the appropriate number of chromosomes (46), how many chromosomes should each sperm and egg have ? Interest Grabber 46 chromosomes 46 + 46 = 92; a developing embryo would not survive if it contained 92 chromosomes. Sperm and egg should each have 23 chromosomes.

3. Planaria animation: http://www.t3.rim.or.jp/~hylas/planaria/title.htm Family http://babyhearing.org/Parenet2Parent/index.asp Remember from Chapter 1: CHARACTERISTICS OF LIVING THINGS ALL LIVING THINGS __________ REPRODUCE

4. ASEXUAL REPRODUCTION Bacteria reproduce using __________________________________ Budding & regeneration are used by plants and animals to reproduce asexually (mitosis) http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookmito.html http://fig.cox.miami.edu/~cmallery/150/mitosis/c7.13.2.hydra.jpg Planaria animation: http://www.t3.rim.or.jp/~hylas/planaria/title.htm BINARY FISSION

5. MITOSIS Produces cells that are __________ copies of parent cell identical

6. ADVANTAGES OF ASEXUAL REPRODUCTION Can make offspring faster Don’t need a partner http://www.mrgrow.com/images/cutting.jpg

7. DISVANTAGES OF ASEXUAL REPRODUCTION ALL ALIKE Species CAN’T change and adapt One disease can wipe out whole population http://www.mrgrow.com/images/cutting.jpg

8. SEXUAL REPRODUCTION Combines genetic material from 2 parents (sperm & egg) so offspring are genetically __________ from parents DIFFERENT Family image from: http://babyhearing.org/Parenet2Parent/index.asp

9. ADVANTAGES OF SEXUAL REPRODUCTION Allows for variation in population Individuals can be different Provides foundation for EVOLUTION Allow species adapt to changes in their environment http://naturalsciences.sdsu.edu/classes/lab8/spindex.html

10. EGG + SPERM  If egg and sperm had same number of chromosomes as other body cells... baby would have too many chromosomes! http://www.angelbabygifts.com/ Image by Riedell http://www.acmecompany.com/stock_thumbnails/13217.forty-six_chromosomes.jpg

11. MEIOSIS is the way… to make cells with ½ the number of chromosomes for sexual reproduction http://waynesword.palomar.edu/lmexer2a.htm

12. Video 1 Click the image to play the video segment 11A. Video 1 Meiosis Overview

13. HAPLOID Some cells have only one copy of each chromosome = _____________ All sperm and egg cells are haploid HAPLOID1n

14. MITOSIS Makes ___ cells genetically _________ to parent cell & to each other Makes ___ cells Makes __________ Used by organisms to: increase size of organism, repair injuries, replace worn out cells http://waynesword.palomar.edu/lmexer2a.htm 2 identical 2n SOMATIC (body)

15. MEIOSIS Makes ____ cells genetically different from parent cell & from each other Makes _____ cells Makes ______________ Used for ____________ 4 1n Gametes (sperm & eggs) sexual reproduction http://waynesword.palomar.edu/lmexer2a.htm

16. WHAT MAKES MEIOSIS DIFFERENT? 1. Exchange of DNA between homologous pairs = _____________ during PROPHASE I CROSSING OVER Allows shuffling of genetic material http:// www.emc.maricopa.edu/faculty/farabee/BIOBK/Crossover.gif

17. HOMOLOGOUS CHROMOSOMES Image modified by Riedell SAME SIZE SAME SHAPE CARRY GENES for the SAME TRAITS BUT ______________! (Don’t have to have the SAME CHOICES) http://sps.k12.ar.us/massengale/genetics%20tutorial.htm NOT IDENTICAL

18. CROSSING OVER Image modified by Riedell Allows for_________________ in different combinations After crossing over, chromatid arms are________________ anymore http://sps.k12.ar.us/massengale/genetics%20tutorial.htm rearranging of DNA NOT IDENTICAL

19. SEGREGATION & CROSSING OVER together make even more combinations See an animation http://waynesword.palomar.edu/lmexer2a.htm

20. MITOSISMITOSIS vs MEIOSIS INTERPHASE INTERPHASE IMEIOSIS DNA is spread out as chromatin Nuclear membrane/ nucleolus visible DNA is copied during S phase Makes stuff new cell needs in G 2 SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

21. MITOSIS vs MEIOSIS PROPHASE PROPHASE I DNA scrunches into chromosomes Nuclear membrane/ nucleolus disappear Centrioles/ spindle fibers appear DNA scrunches into chromosomes Nuclear membrane/ nucleolus disappear Centrioles/spindle fibers appear Homologous pairs match up http://www.pbs.org/wgbh/nova/baby/divi_flash.html

22. MITOSIS vs MEIOSIS METAPHASE METAPHASE I Chromosomes line up in middle http://www.pbs.org/wgbh/nova/baby/divi_flash.html with homologous partner

23. MITOSIS vs MEIOSIS ANAPHASE ANAPHASE I APART: Chromatids split APART: http://www.pbs.org/wgbh/nova/baby/divi_flash.html Chromatids stay together Homologous pairs split

24. MITOSIS vs MEIOSIS TELOPHASE TELOPHASE I See TWO nuclei Nuclear membrane/ nucleolus return DNA spreads out as chromatin Spindle/centrioles disappear SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

25. MITOSIS vs MEIOSIS CYTOKINESIS CYTOKINESIS I Cytoplasm splits into 2 cells SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

26. MITOSIS vs MEIOSIS INTERPHASE II DNA is spread out as chromatin Nuclear membrane/ nucleolus visible DNA is copied during S phase SKIP INTERPHASE II DNA NOT COPIED http://www.pbs.org/wgbh/nova/baby/divi_flash.html

27. MITOSIS vs MEIOSIS PROPHASE PROPHASE II DNA scrunches into chromosomes Nuclear membrane/ nucleolus disappear Centrioles/ spindle fibers appear SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

28. MITOSIS vs MEIOSIS METAPHASE METAPHASE II Chromosomes line up in middle SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

29. MITOSIS vs MEIOSIS ANAPHASE ANAPHASE II Chromatids split and move apart SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

30. MITOSIS vs MEIOSIS TELOPHASE TELOPHASE II Two nuclei Nuclear membrane/ nucleolus returns Centrioles/spindle fibers disappear DNA spreads out as chromatin SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

31. MITOSIS vs MEIOSIS CYTOKINESIS CYTOKINESIS II Cytoplasm splits SAME AS MITOSIS http://www.pbs.org/wgbh/nova/baby/divi_flash.html

32. MAKING SPERM & EGGS

33. ___________________= MAKING MATURE SPERM Mature & grow flagella SPERMATOGENESIS

34. Sperm provides DNA All the starting nutrients, organelles, molecule building blocks, etc. have to come from the egg.

35. POLAR BODIES Produces: 1 “good” egg 3 CYTOPLASM DIVIDES UNEVENLY __________________ = MAKING a MATURE EGG OOGENESIS

36. Sperm donates mostly DNA http://bestweekever.blogs.com/photos/uncategorized/imagemain_sperm_egg1_1.gif WHY MAKE ONLY ONE “GOOD” EGG? Most of the cell parts and nutrients needed for baby come from EGG!