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Asexual Reproduction

Asexual Reproduction. Reproduction not involving the union of gametes Ex: mitosis Ex: Budding and Binary fission. Binary Fission. An asexual cell division of prokaryotes that produces identical offspring Ex, bacteria dividing by mitosis. A budding Yeast cell. A dividing bacterium.

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Asexual Reproduction

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  1. AsexualReproduction

  2. Reproduction not involving the union of gametes • Ex: mitosis • Ex: Budding and Binary fission

  3. Binary Fission

  4. An asexual cell division of prokaryotes that produces identical offspring • Ex, bacteria dividing by mitosis. A budding Yeast cell A dividing bacterium

  5. Sexual Reproduction

  6. Combination of two set of DNA to form a diploid organism. • Can be external as in fish, amphibians or • internal as in mammals.

  7. DNA Replication

  8. An exact DNA copy is made. • A process called “semiconservative replication” because the DNA has one old strand on one new strand.

  9. The process of DNA Replication

  10. DNA separates at the base pair/hydrogen bond • DNA polymerase attaches the complementary DNA nucleotides • Two identical strands are made, one new and one is the old.

  11. DNA replication animation http://www.tracy.k12.ca.us/thsadvbio/OnlineLessons.htm http://207.207.4.198/pub/flash/24/menu.swf

  12. Mitosis

  13. A process where chromosomes replicate and are separated to separate cells. • One cell divides into two identical cells • Diploid number of chromosomes • Phases of mitosis are: prophase, metaphase, anaphase and telophase. Two cells result after cytokinesis or the divison of the cytoplasm

  14. The Cell Cycle

  15. When a cell first is formed to when it divides ( either by mitosis or meiosis) • Stages include: Interphase (growth and DNA replication), Mitosis and Cytokinesis

  16. Interphase

  17. Stage of the cell cycle where the cell is: G1(first growth): growing in cytoplasm S( Synthesis): DNA replication G2(second growth): organelles, especially centrioles replicate.

  18. Prophase

  19. Phase of mitosis where the nucleus and nucleolus begin to disintegrate, the DNA condenses into chromosomes and cenrioles begin to separate to opposite ends of the cell. (centrioles)

  20. Metaphase

  21. Phase of mitosis where the chromosomes ( already replicated and look like “X”) line up ion the center ( metaphase plate)

  22. Anaphase

  23. Phase of Mitosis where the sister chromotids separate ( replicate chromosomes) and move to opposite ends of the cell. They are moved by the spindle fibers retracting into the centriole

  24. Telophase

  25. Phase of mitosis where the cell begins to pinch into two ( animal cells form a cleavage furrow and plant cells begin to form a new cell plate). Two identical cells are produced. The nucleus and nucleolus reform. Animal cell Plant cell Cytokinesis is when there are actually two cells

  26. Animal cell Mitosis compared to Plant cell mitosis

  27. Animal Plant -Centrioles present - no centrioles -Centrioles produce spindles -Cytoskeleton produces spindles -Cleavage furrow (pinching in) -new cell plate/wall formed to produce 2 cells to produce 2 cells

  28. Mitosis animation http://www.ai.mit.edu/lab/olympics/98/events/MITosis/mitosis-animation.gif http://web.grcc.edu/biosci/pictdata/mitosis/planmito.htm (plant)

  29. Diploid

  30. A cell that contains both chromosomes of a homologous pair. • One set of chromosomes from each parent • Union of an egg (23 chromosomes) and a sprem (23 chromosomes) results in a zygote with 46 chromosomes or the diploid number of chromosomes ( for humans)

  31. Somatic

  32. Body cells (all except gametes) • Produced by mitosis • Have the diploid number of chromosomes or 46 in humans Ex: Skin, muscle, nerve…

  33. Gamete

  34. A reproductive cell • Eggs and sperm cells • These cells contain the haploid number of chromosomes ( half the full set) • In humans this is 23 chromosomes • These cells are produced by Meiosis of special somatic cells (eggs by oogonia and sperm by spermatogonia). • The Cell Cycle for these cells ends with gamete formation.

  35. Haploid

  36. Having only one chromosome of each homologous pair • Gametes are haploid or contain 23 chromosomes • Haploid cells combine to form diploid cells as in fertilization ( egg combines with sperm)

  37. Meiosis

  38. The process of nuclear division that reduces the number of chromosomes in a cell by half • In humans, the parent cell of the gametes has 46 chromosomes (diploid number). This cell divides by Meiosis to produce four halpoid cells with 23 chromosomes.

  39. First Division of Meiosis

  40. The replicated sets of chromosomes pair up into tetrads, the tetrads line up on the metaphase plate and are separated. This division results in two cells with replicate sets of chromosomes. They still need to separate (the second division)

  41. Second division of Meiosis

  42. From the first division where there are two cells with replicate sets of the haploid number of chromosomes, the two cells now divide similar to MITOSIS and four cells with one copy of a haploid set of chromosomes is the result.

  43. Crossing Over

  44. The exchange of genes by reciprocal segments of homologous chromosomes during meioses • This occurs during prophase and metaphase of meiosis I.

  45. Meiosis animation http://www.sumanasinc.com/webcontent/animations/content/meiosis.html

  46. Fertilization

  47. Joining of two gametes to produce a diploid zygote egg sperm

  48. Zygote

  49. The diploid cell that results from the fusion of gametes DNA from sperm = zygote DNA from egg

  50. RNA

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