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Reproduction

Reproduction. Asexual vs. Sexual. Asexual Reproduction. Asexual reproduction is the formation of new individuals from the cells of a single parent. It is very common in plants; less so in animals.

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Reproduction

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  1. Reproduction Asexual vs. Sexual

  2. Asexual Reproduction • Asexual reproduction is the formation of new individuals from the cells of a single parent. It is very common in plants; less so in animals. • Or in the case of cells, asexual reproduction is making a new cell that is the same as the parent cell.

  3. Asexual Reproduction in Plants—Stems!!! • All plant organs have been used for asexual reproduction, but stems are the most common. • In some species, stems arch over and take root at their tips, forming new plants. • The horizontal above-ground stems of the strawberry produce new daughter plants.

  4. Asexual Reproduction in Plants—Leaves!! • This photo shows the leaves of the plant Bryophyllum. Mitosis along the leaf margins produces tiny plantlets that fall off and form new plants.

  5. Asexual Reproduction in Plants—Roots! • Some plants use their roots for asexual reproduction. • The dandelion is a common example. • Trees, such as the poplar or aspen, send up new stems from their roots. In time, an entire grove of trees may form — all part of a clone of the original tree.

  6. Asexual Reproduction in Plants—Plant propagation by people • Commercially-important plants are often deliberately propagated by asexual means in order to keep particularly desirable traits (e.g., flower color, flavor, resistance to disease). • Cuttings may be taken from the parent and rooted. • Grafting is widely used to propagate a desired variety of shrub or tree. All apple varieties, for example, are propagated this way.

  7. Asexual Reproduction in Animals--Budding • In budding, offspring develop as a growth on the body of the parent. • In some species, e.g., jellyfishes and many echinoderms, the buds break away and take up an independent existence. • In others, like corals, the buds remain attached to the parent and the process results in colonies of animals. • Budding is also common among parasitic animals, e.g., tapeworms.

  8. Asexual Reproduction in Animals--Parthenogenesis • In parthenogenesis ("virgin birth"), the females produce eggs, but these develop into young without ever being fertilized. • Parthenogenesis occurs in some fishes, several kinds of insects, and a few species of frogs and lizards.

  9. Sharks!!!

  10. Ants!!! I hate ants 

  11. Crayfish?

  12. Lizards

  13. Komodo Dragons!!!

  14. So why don’t all organisms reproduce asexually? • You don’t have to waste all that time finding a mate. And you get to pass on all of your own genes!!!

  15. The advantages of Sexual reproduction • Sexual reproduction allows for greater diversity. • “Bad genes” can get covered up by good ones from the other parent. • Combinations of genes make it so organisms can better deal with changing environments.

  16. So, now for cells and asexual reproduction. • The cell cycle asexually produces new body cells for: • Repair • Replacement • Growth

  17. The Cell Cycle • The cell cycle consists of three main parts. • Interphase • Mitosis • Cytokinesis

  18. Interphase • During interphase, the cell is preparing to divide by making more organelles and copying its DNA.

  19. Mitosis • Mitosis is when the cell is actually making the new cells. It consists of 4 steps or phases. • Prophase • Metaphase • Anaphase • Telophase

  20. Prophase • During prophase, the chromatin condenses into chromosomes.

  21. Metaphase • During metaphase, chromosomes line up in the middle of the cell

  22. Anaphase • Anaphase is when the chromosomes move to the opposite ends.

  23. Telophase • In telophase, the chromosomes reach the opposite ends and the cell gets ready to actually split.

  24. Cytokinesis • During cytokinesis, the cell divides into two cells.

  25. Results of Mitosis • Produces new body cells • Cell copies DNA once • Cell splits once • 2 new (daughter) cells • Daughter cells the same as the parent cells • Daughter cells have the same number of chromosomes as the parent cells

  26. Cells and Sexual Reproduction • A different type of cell must be produced for sexual reproduction. • These different cell are called sex cells, or gametes • Egg = female gamete • Sperm = male gamete

  27. Gametes!!! • Since the gametes are going to unite to make a new organism, each gamete only needs to have half the genetic information as its parent cell. • In mitosis, the cell copied its DNA once and split once. • In making sex cells, the cell has to copy it’s DNA once and then split twice.

  28. Meiosis • The process of making gametes by copying the DNA once, and splitting twice is called meiosis.

  29. Results of Meiosis • Produces gametes (Sex cells) • Cell copies DNA once • Cell splits twice • 4 new (daughter) cells • Daughter cells different from parent cells • Daughter cells have the half the number of chromosomes as the parent cells

  30. Cell Division Comparison Mitosis Meiosis • Produces body cells • Cell copies DNA once • Cell splits once • 2 new (daughter) cells • New cells the same as the parent cells • Daughter cells have the same number of chromosomes as the parent cells • Produces gametes • Cell copies DNA once • Cell splits twice • 4 new (daughter) cells • New cells different from parent cells • Daughter cells have the half the number of chromosomes as the parent cells

  31. Bibliography • http://ron.outcrop.org/images/dandelions.jpg • http://www.jensartblog.com/uploaded_images/pathway_through_the_quaking_aspens-%28Small%29-793568.jpg • http://www.theflowerexpert.com/media/images/mostpopularflowers/roses/assorted-roses.jpg • http://h2o-mag.com/issue6/images_issue6/coral-01-copy.jpg • http://www.youtube.com/watch?v=aOVd2DLE_0w • http://www.elasmodiver.com/Sharkive%20images/Bonnethead-shark-003.jpg • http://2.bp.blogspot.com/_StLk5qXxAv0/STyDpxr0TLI/AAAAAAAAAUs/0bdZZoDksnA/s400/tapeworm.jpg • http://www.nt.gov.au/nreta/wildlife/programs/exotic_ants/images/smaller/electric_ant.jpg • http://www.geocities.jp/ideryusei/marmorkrebs_blau_1.jpg • http://upload.wikimedia.org/wikipedia/en/thumb/3/36/Cnemidophorus-ThreeSpecies.jpg/260px-Cnemidophorus-ThreeSpecies.jpg • http://www.youtube.com/watch?v=bdX7wcoycuQ&feature=related • http://dummidumbwit.files.wordpress.com/2009/09/komodo_dragon-1.jpg • http://skew.dailyskew.com/uploaded_images/komodo-dragon-731086.jpg • http://twelfthjen.files.wordpress.com/2009/07/how-to-end-a-bad-date-1.jpg • http://delvecarahe.files.wordpress.com/2008/01/homer-clones.jpg • http://samismom22.files.wordpress.com/2009/09/loads_of_worms.jpg • http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Lectures/mitosis/whitefish_mitosis_interphase_X_400_small.jpg • http://micro.magnet.fsu.edu/micro/gallery/mitosis/lateprophase.jpg • http://images.google.com/imgres?imgurl=http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/metaphase1_pc.jpg&imgrefurl=http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/pcmetaphase.html&usg=__vpdn5EQkNkv3NYQ3Ys_BX_51ZqU=&h=270&w=360&sz=41&hl=en&start=4&sig2=W4syDm81YnC5BCAdNbiV6g&um=1&itbs=1&tbnid=BPdNkm2cwZ3kZM:&tbnh=91&tbnw=121&prev=/images%3Fq%3Dmetaphase%26hl%3Den%26client%3Dfirefox-a%26rlz%3D1R1GGLL_en___US363%26sa%3DN%26um%3D1&ei=82tvS_HEHoreMd7MsN8E • http://www.vtt.fi/kuvat/uutta/Cytokinesis_driven_by_Rab21.jpg • http://botit.botany.wisc.edu/images/130/Mitosis/Allium_Root_Prep._Slides/telophase_cytokinesis.low.jpg • http://images.google.com/imgres?imgurl=http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/images/early_anaphase1_pc.jpg&imgrefurl=http://student.ccbcmd.edu/courses/bio141/lecguide/unit6/genetics/DNA/DNArep/pcanaphaseA.html&usg=__6ittd9CxuOIqGVNdT90YA6eFDbU=&h=270&w=360&sz=41&hl=en&start=3&sig2=nzPNOMhAd0Iiy4oOk5Gssg&um=1&itbs=1&tbnid=9HdrVNA-SKYGuM:&tbnh=91&tbnw=121&prev=/images%3Fq%3Danaphase%26hl%3Den%26client%3Dfirefox-a%26rlz%3D1R1GGLL_en___US363%26sa%3DG%26um%3D1&ei=hmxvS_bAMJPENb-r_dUE • http://www.youtube.com/watch?v=uh7c8YbYGqo&feature=related

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