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

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

ASEXUAL REPRODUCTION Bacteria reproduce using http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookmito.html Bacteria reproduce using __________________________________ Budding & regeneration are used by plants and animals to reproduce asexually (mitosis) 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

MITOSIS Produces cells that are __________ copies of parent cell

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

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

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

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

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

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

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

DIPLOID & HAPLOID HOMOLOGOUS CHROMOSOMES Most cells have 2 copies of each chromosome = ______________ (one from mom; one from dad) All BODY (___________) cells are diploid HOMOLOGOUS CHROMOSOMES

DIPLOID & HAPLOID Some cells have only one copy of each chromosome = _____________ All sperm and egg cells are haploid

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

MEIOSIS Makes ____ cells genetically different from parent cell & from each other Makes _____ cells Makes ______________ Used for ____________ http://waynesword.palomar.edu/lmexer2a.htm

WHAT MAKES MEIOSIS DIFFERENT ? SYNAPSIS & CROSSING OVER (PROPHASE I) SEGREGATION & INDEPENDENT ASSORTMENT (ANAPHASE I) 3. Skip INTERPHASE II (NO S) CELL DIVIDES TWICE, BUT… ONLY COPIES DNA ONCE

WHAT MAKES MEIOSIS DIFFERENT ? Homologous chromosomes pair up during ____________= ______________ This group of FOUR (4) chromatids is called a _________________ Images modified from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/Crossover.gif

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

Click the image to play the video segment. 11E Crossing Over SEE CROSSING OVER ANIMATION Click the image to play the video segment. 11E Video 5

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

Allows for_________________ in different combinations Image modified by Riedell CROSSING OVER Allows for_________________ in different combinations After crossing over, chromatid arms are________________ anymore http://sps.k12.ar.us/massengale/genetics%20tutorial.htm

WHAT MAKES MEIOSIS DIFFERENT ? 2.Separation during ANAPHASE I __________________ & _______________________ Separates gene choices and allows shuffling of genetic material

Click the image to play the video segment 11D. Segregation of Chromosomes Click the image to play the video segment 11D. Video 4

SEGREGATION (Anaphase I)

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

INDEPENDENT ASSORTMENT http://fig.cox.miami.edu/~cmallery/150/mitosis/c13x9independent-assortment.jpg

INDEPENDENT ASSORTMENT at ANAPHASE I Lots of different combinations are possible! This is why you don’t look exactly like your brothers and sisters even though you share the same parents!

http://www.tokyo-med.ac.jp/genet/anm/mimov.gi

WHAT MAKES MEIOSIS DIFFERENT ? Crossing over Segregation Independent assortment are ALL ways MEIOSIS results in =______________________________ So daughter cells are ______________ from parents and from each other

WHAT MAKES MEIOSIS DIFFERENT ? 3. Skip INTERPHASE II (No S) CELL DIVIDES TWICE, BUT … ONLY COPIES ITS DNA ONCE MITOSIS: G1 S G2 P M A T C        MEIOSIS: ( I ) G1 A T C S G2 P M        P M A T C ( II )    

Click the image to play the video segment 11B. & C Animal Cell Meiosis, Part 1 & Part 2 Click the image to play the video segment 11B. & C

Figure 11-15 Meiosis Section 11-4 Meiosis I

Figure 11-17 Meiosis II Meiosis II Section 11-4 Prophase II Metaphase II Anaphase II Telophase II Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original. The chromosomes line up in a similar way to the metaphase stage of mitosis. The sister chromatids separate and move toward opposite ends of the cell. Meiosis II results in four haploid (N) daughter cells.

MITOSIS vs MEIOSIS INTERPHASE INTERPHASE I http://www.pbs.org/wgbh/nova/baby/divi_flash.html DNA is spread out as chromatin Nuclear membrane/ nucleolus visible DNA is copied during S phase Makes stuff new cell needs in G2 _______________

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

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

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

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

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

MITOSIS vs MEIOSIS INTERPHASE II http://www.pbs.org/wgbh/nova/baby/divi_flash.html DNA is spread out as chromatin Nuclear membrane/ nucleolus visible DNA is copied during S phase __________________ __________________ __________________

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

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

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

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

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

Ways Meiosis is different? Homologous pairs match up & trade DNA (SYNAPSIS & CROSSING OVER) in PROPHASE I SEGREGATION & INDEPENDENT ASSORTMENT in Anaphase I create genetic recombination Skipping INTERPHASE II- (Dividing TWICE but copying DNA once) produces 1n cells

MAKING SPERM & EGGS

___________________= MAKING MATURE SPERM Mature & grow flagella

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

__________________ = MAKING a MATURE EGG Produces: 1 “good” egg 3 __________ CYTOPLASM DIVIDES UNEVENLY

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

POLAR BODIES DEGENERATE (DIE) “Self digest” Using ________________ = __________________ “cell suicide” for good of organism