1. Cell Reproduction Chapters 10 & 11 OCC BIO-114 Dave Werner

2. Video/Animation Eukaryotic Cell Reproduction Eukaryotic Cell Reproduction Eukaryotic Cell Reproduction Eukaryotic Cell Reproduction Mitosis set to Music Mitosis set to Music Mitosis set to Music Mitosis set to Music Mitosis Animation Mitosis Animation Mitosis Animation Mitosis Animation

3. Chromosomes During cell division, the DNA in a eukaryotic cell’s nucleus is coiled tightly into Chromosomes Each Chromosome is a single DNA molecule associated with proteins ChromosomeDNA molecule

4. Histones and Nonhistones Histones are proteins that the DNA wrap around, and help maintain the shape of the chromosome Histones are proteins that the DNA wrap around, and help maintain the shape of the chromosome Nonhistones are proteins that are involved in controlling activity of the DNA Nonhistones are proteins that are involved in controlling activity of the DNA

5. Chromosomes fig.10.5/10.7 Each chromosome is made up of 2 identical chromatids Each chromosome is made up of 2 identical chromatids The chromatids are held together by the centromere The chromatids are held together by the centromere In humans, we have 23 pairs of chromosomes In humans, we have 23 pairs of chromosomes Or 46 chromosomes Or 46 chromosomes Or 92 chromatids Or 92 chromatids

6. REMEMBER….. The number of chromosomes that a species has does NOT reflect on how complex that animal may or may not be!!! The number of chromosomes that a species has does NOT reflect on how complex that animal may or may not be!!! Pairs of chromosomes Pairs of chromosomes Mosquito 3Housefly 6 Garden onion 8Rice12 Frog 13Cat19 House mouse 20Wheat 21 Human 23 Potato 24 Cattle 30Donkey 31 Horse 32Dog 39 Carp 52

7. Chromosomes Human and animal chromosomes are categorized as either sex chromosomes or autosomes What name do we give the sex chromosomes of humans? Hint: 2 letters X & Y

8. Sex chromosomes fig.10.6 These chromosomes determine the sex of an organism, and may carry genes for other characteristics These chromosomes determine the sex of an organism, and may carry genes for other characteristics Only 1 pair of chromosomes are considered sex chromosomes, while the other 22 pairs are autosomes Only 1 pair of chromosomes are considered sex chromosomes, while the other 22 pairs are autosomes

9. Autosomes Each cell contains 2 copies of each autosome. Each cell contains 2 copies of each autosome. In other words, an autosome is a chromosome, so there are 2 identical chromosomes, for each of the 22 autosomes In other words, an autosome is a chromosome, so there are 2 identical chromosomes, for each of the 22 autosomes Chromosomes are made up of 2 identical chromatids. Chromosomes are made up of 2 identical chromatids. Therefore, how many chromatids are found in each pair of autosomes?

10. Autosomes The two copies of each autosome are called homologous chromosomes or homologues because there are the same size, shape, and carry the same genes for specific traits…EVEN though they come from two separate parents! The two copies of each autosome are called homologous chromosomes or homologues because there are the same size, shape, and carry the same genes for specific traits…EVEN though they come from two separate parents!

11. Fruit Fly The Fruit Fly contains 8 chromosomes The Fruit Fly contains 8 chromosomes How many of those 8 are sex chromosomes? How many of those 8 are sex chromosomes? 2 How many of those 8 are autosomes? How many of those 8 are autosomes? 6 How many homologous pairs are present? How many homologous pairs are present? 4 If each chromosome is made up of 2 chromatids, how many chromatids does this fly have in EACH cell? If each chromosome is made up of 2 chromatids, how many chromatids does this fly have in EACH cell? 16 16

12. Karyotype fig.10.6 A Karyotype is a photomicrograph of all the chromosomes found in a cell that are paired up into homologues based on their size and shape A Karyotype is a photomicrograph of all the chromosomes found in a cell that are paired up into homologues based on their size and shape

13. Diploid (2n) cells Cells having 2 sets of chromosomes are considered to be diploid or 2n. Cells having 2 sets of chromosomes are considered to be diploid or 2n. Every cell in the human body EXCEPT reproductive cells (sperm and egg cells) are diploid or 2n Every cell in the human body EXCEPT reproductive cells (sperm and egg cells) are diploid or 2n

14. Haploid 1n cells Sperm and egg cells are haploid or 1n cells. Sperm and egg cells are haploid or 1n cells. When the haploid 1n sperm and the haploid 1n egg cells join together, what do they form? When the haploid 1n sperm and the haploid 1n egg cells join together, what do they form? Why do the sex cells only contain 1 set of chromosomes rather than 2? Why do the sex cells only contain 1 set of chromosomes rather than 2?

15. Cell Division Binary Fission is the division of prokaryotic cells into identical cells Binary Fission is the division of prokaryotic cells into identical cells The chromosome makes a copy of itself The chromosome makes a copy of itself The cell continues to grow until it is doubled in size The cell continues to grow until it is doubled in size A Cell wall forms between the 2 chromosomes A Cell wall forms between the 2 chromosomes The cell splits into 2 new cells The cell splits into 2 new cells

16. Binary Fission Binary Fission STAGE 1 - The Chromosome, which is attached to the Inside of the Cell Membrane, makes a COPY of Itself, Resulting in Two Identical Chromosomes Attached to the Inside of the Inner Cell Membrane. STAGE 2 - The Cell continues to grow until it reaches approximately TWICE its Normal Size. Then a CELL WALL Begins forms between the Two Chromosomes. STAGE 3 - The Cell SPLITS into TWO NEW CELLS. Each New Cell contains on the Identical Chromosomes

17. Cell Division Mitosis results in new cells with genetic material that is identical to that of the original cell Mitosis results in new cells with genetic material that is identical to that of the original cell

18. Cell Cycle fig.10.8 Cell cycle is the repeating set of events that make up the life of a cell, with cell division making up only one phase Cell cycle is the repeating set of events that make up the life of a cell, with cell division making up only one phase

19. Cell Cycle Interphase – Majority of the cell lifetime Interphase – Majority of the cell lifetime 1. G 1 Phase Cells grow to a mature size 2. S Phase DNA within the cell is copied 3. G 2 Phase Cell prepares for cell division

20. Cell Cycle Mitosis or M Phase Division of the Nucleus

21. Mitosis fig.10.11 1. Prophase 1. Prophase DNA is tightly coiled into chromosomes, which is made up of 2 chromatids held together by the centromere DNA is tightly coiled into chromosomes, which is made up of 2 chromatids held together by the centromere Remember that the chromosomes were copied during the S Phase of Interphase Remember that the chromosomes were copied during the S Phase of Interphase Nucleolus and Nuclear membrane break down and disappear Nucleolus and Nuclear membrane break down and disappear Two pairs of centrosomes appear each made up of 2 centrioles Two pairs of centrosomes appear each made up of 2 centrioles Plant cells do not contain centrioles Plant cells do not contain centrioles

22. Mitosis 1. Prophase (Continued) 1. Prophase (Continued) Centrosomes move toward opposite poles of the cell Centrosomes move toward opposite poles of the cell Spindle fibers made up of microtubules radiate from the centrosomes which make up the mitotic spindle Spindle fibers made up of microtubules radiate from the centrosomes which make up the mitotic spindle

24. Spindle Fibers 1. Kinetochore fibers attached to a protein called kinetochore found in the centromere region 1. Kinetochore fibers attached to a protein called kinetochore found in the centromere region These fibers extend from the chromatid to the kinetochore These fibers extend from the chromatid to the kinetochore 2. Polar Fibers extend from one centrosome to the other 2. Polar Fibers extend from one centrosome to the other

25. Mitosis 2. Metaphase 2. Metaphase Kinetochore fibers move the choromosomes to the center of the cell, and then hold them in place Kinetochore fibers move the choromosomes to the center of the cell, and then hold them in place

27. Mitosis 3. Anaphase 3. Anaphase Chromatids of each chromosome separate at the centromere and slowly move toward opposite poles of the cell Chromatids of each chromosome separate at the centromere and slowly move toward opposite poles of the cell

29. Mitosis 4. Telophase 4. Telophase Spindle fibers disassemble and the chromosomes begin to uncoil Spindle fibers disassemble and the chromosomes begin to uncoil Nuclear envelope and Nucleolus form Nuclear envelope and Nucleolus form

31. Cytokinesis Cytoplasm of the cell divides Cytoplasm of the cell divides Cell membrane “Pinches off” and separates into 2 cells Cell membrane “Pinches off” and separates into 2 cells In plants, rather than pinching off, since cell walls are so hard, a cell plate is formed by the Golgi apparatus In plants, rather than pinching off, since cell walls are so hard, a cell plate is formed by the Golgi apparatus

33. fig.10.14

34. Mitosis

35. BioClip – Mitosis Animation http://www.loci.wisc.edu/outreach/bioclips/C DBio.html http://www.loci.wisc.edu/outreach/bioclips/C DBio.html http://www.loci.wisc.edu/outreach/bioclips/C DBio.html http://www.loci.wisc.edu/outreach/bioclips/C DBio.html

36. Tumors & Cancer Tumor = cells dividing at an abnormally high rate. Tumor = cells dividing at an abnormally high rate. Neoplasms = Moles & other tumors Neoplasms = Moles & other tumors Benign Tumors = Not harmful Benign Tumors = Not harmful Malignant Tumors = Cancer Malignant Tumors = Cancer Metastasis – rapid growth & spreading Metastasis – rapid growth & spreading

37. Meiosis – Ch.11 MeiosisVideo

38. Meiosis While Mitosis is the division of body cells into exact copies, meiosis is the division of cells twice to form sex cells (Sperm and Egg) While Mitosis is the division of body cells into exact copies, meiosis is the division of cells twice to form sex cells (Sperm and Egg) EGGS are larger than sperm and contain a lot of Cytoplasm. An egg is nonmotile. EGGS are larger than sperm and contain a lot of Cytoplasm. An egg is nonmotile. SPERM Cells contain very little Cytoplasm, have Flagella, that helps them swim to the nonmotile egg SPERM Cells contain very little Cytoplasm, have Flagella, that helps them swim to the nonmotile egg The Chromosomes of Two Gametes are added together when they join. The Chromosomes of Two Gametes are added together when they join.

39. Meiosis Cells that undergo Meiosis divide twice. Cells that undergo Meiosis divide twice. The first cell division is known as Meiosis I The first cell division is known as Meiosis I The second cell division is known as Meiosis II The second cell division is known as Meiosis II Rather than one cell forming two diploid cells (2n), like in mitosis, the cells form 4 haploid (1n) cells in meiosis. Rather than one cell forming two diploid cells (2n), like in mitosis, the cells form 4 haploid (1n) cells in meiosis.

40. Meiosis I Prophase I DNA coils tightly into chromosomes Spindle fibers appear Nucleus and Nucleolus disappear Chromosomes line up with its homologue Synapsis is the pairing of homologous chromosomes

41. Meiosis I Prophase I Prophase I Tetrad is the pair of homologous chromosomes Tetrad is the pair of homologous chromosomes Tetrad = 4 because there are 4 chromatids for each homologous pair… like a tetrapod! During synapsis, chromatids within a homologous pair twist around one another Tetrad = 4 because there are 4 chromatids for each homologous pair… like a tetrapod! During synapsis, chromatids within a homologous pair twist around one another

42. Meiosis I (fig.11.8) Prophase I Prophase I Portions of Chromatids may Break Off and attach to Adjacent Chromatids on the homologous Chromosome - a process called CROSSING-OVER Portions of Chromatids may Break Off and attach to Adjacent Chromatids on the homologous Chromosome - a process called CROSSING-OVER Crossing Over results in genetic recombination Crossing Over results in genetic recombination

43. Meiosis I Metaphase I Metaphase I Tetrads line up along the mid-line of the dividing cell (think meta – middle) Tetrads line up along the mid-line of the dividing cell (think meta – middle) Spindle fibers from each pole attach to the centromeres of each of the homologues Spindle fibers from each pole attach to the centromeres of each of the homologues

44. Meiosis I Anaphase I Anaphase I Each homologous chromosome moves to opposite poles of the dividing cells Each homologous chromosome moves to opposite poles of the dividing cells The separation of the homologous chromosomes is known as independent assortment, which is another way for genetic variation The separation of the homologous chromosomes is known as independent assortment, which is another way for genetic variation

45. Meiosis I Telophase I Telophase I Chromosomes reach opposite ends of the cell, and cytokinesis begins Chromosomes reach opposite ends of the cell, and cytokinesis begins

46. Meiosis I (fig.11.8)

47. Meiosis II Prophase II Prophase II Spindle fibers form and begin to move the chromosomes toward the midline of the dividing cell Spindle fibers form and begin to move the chromosomes toward the midline of the dividing cell Metaphase II Metaphase II Chromosomes move to the midline of the dividing cell facing opposite poles Chromosomes move to the midline of the dividing cell facing opposite poles Anaphase II Anaphase II Chromatids separate and move toward opposite poles of the cell Chromatids separate and move toward opposite poles of the cell Telophase II Telophase II Nuclear membrane forms around the chromosomes in each of the 4 new cells which contain HALF of the original cell’s # of chromosomes = 4 Haploid offspring cells. Nuclear membrane forms around the chromosomes in each of the 4 new cells which contain HALF of the original cell’s # of chromosomes = 4 Haploid offspring cells.

48. Meiosis II (fig.11.7/11.8)

49. Meiosis Meiosis occurs in only the reproductive organs Meiosis occurs in only the reproductive organs In humans, meiosis occurs in the testes and ovaries In humans, meiosis occurs in the testes and ovaries

50. Formation of Gametes In the testes, meiosis produces sperms cells or spermatozoa. In the testes, meiosis produces sperms cells or spermatozoa. A diploid (2n) reproductive cell divides meiotically to form 4 haploid (1n) cells called spermatids A diploid (2n) reproductive cell divides meiotically to form 4 haploid (1n) cells called spermatids The production of sperm cells is called spermatogenesis The production of sperm cells is called spermatogenesis In the ovaries, meiosis produces egg cells or ova In the ovaries, meiosis produces egg cells or ova A diploid (2n) reproductive cell divides meiotically to form 1 haploid (1n) cell called ovum, and 3 haploid (1n) polar bodies which eventually degenrate A diploid (2n) reproductive cell divides meiotically to form 1 haploid (1n) cell called ovum, and 3 haploid (1n) polar bodies which eventually degenrate The production of and egg cell is called oogenesis The production of and egg cell is called oogenesis

51. Spermatogenesis (fig.11.3)

52. Oogenesis (fig.11.3)

53. Asexual Reproduction Asexual reproduction is the production of offspring from one parent. Asexual reproduction is the production of offspring from one parent. Usually does not involve meiosis or gametes. Usually does not involve meiosis or gametes. Most commonly by binary fission or mitosis Most commonly by binary fission or mitosis Offspring is identical to parent Offspring is identical to parent

54. Sexual Reproduction Sexual Reproduction is the production of offspring through meiosis and the union of a sperm and an egg. Sexual Reproduction is the production of offspring through meiosis and the union of a sperm and an egg. Offspring produced are genetically different from parents Offspring produced are genetically different from parents Allows for genetic variation Allows for genetic variation

55. Comparing Mitosis to Meiosis NOVA Online = good study tool NOVA Online = good study tool NOVA Online = good study tool NOVA Online = good study tool Can you identify the differences/Similarities??? Can you identify the differences/Similarities???