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Cell Reproduction. Chromosomes: made of DNA DNA: stores all genetic information -genes: a hereditary unit of DNA -4 bases: -Adenine -Thymine -Guanine.

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Presentation on theme: "Cell Reproduction. Chromosomes: made of DNA DNA: stores all genetic information -genes: a hereditary unit of DNA -4 bases: -Adenine -Thymine -Guanine."— Presentation transcript:

1 Cell Reproduction

2 Chromosomes: made of DNA

3 DNA: stores all genetic information -genes: a hereditary unit of DNA -4 bases: -Adenine -Thymine -Guanine -cytosine

4 DNA in the Cell 1.Chromosome 2.Supercoil 3.Subcoil 4.One coil 5.DNA with histine protein 6.DNA

5 Chromosome Anatomy

6 Chromosome Types 1.Sex Chromosomes: determines the sex of an organism -XY: male -XX: female 2.Autosomes: All other chromosomes of an organism

7 Chromosome Duplication

8 Homologous Chromosomes: two copies of each autosome – same size, shape, and genes

9 Karyotype: photomicrograph of chromosomes Humans have 22 pairs of autosomes and 1 pair of sex chromosomes

10 Diploid Cells (2n): cells with both sets of chromosomes (both homologous pairs) 46 chromosomes/23 pairs in humans

11 Haploid cells (1n): cells with one set of chromosomes

12 “C” words of Cytology 1. Chromosome: condensed genetic material 2.Chromatid: one of two identical copies of DNA 3.Centromere: region that joins the chromatids

13 “C” words of Cytology 4.Centrioles: cylindrical structures that assist in cell division 5.Centrosome: dark regions in the cytoplasm that create spindle fibers

14 Cell Division: all cells come from pre- existing cells

15 2 Types of Division

16 1. Mitosis: cell division which produces 2 diploid, identical cells

17 2. Meiosis: cell division which produces 4 haploid cells

18 Cell Life Cycle 1.Interphase: G1, S, and G2 G = growth S = Synthesis 2.M phase: mitosis – nuclear division 3.Cytokinesis: cytoplasm division

19 Interphase 1. Interphase: DNA not visible -nucleus still intact

20 Phases of Mitosis 2.Prophase: chromosomes become visible -nucleus disintegrates

21 Phases of Mitosis 3.Metaphase: chromosomes connect at the centromere to spindle fibers -line up at the equatorial plate

22 Phases of Mitosis 4.Anaphase: spindle fibers recede -pull chromosomes apart -chromosomes retreat to opposite ends

23 Phases of Mitosis 5.Telophase: nucleus reforms Cytokinesis splitting the cell -2 daughter cells are formed

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28 Meiosis: cell division which produces 4 haploid cells

29 Haploid: a cell with half the number of chromosomes (1n)

30 Fertilization: the fusion of two gametes (sperm/eggs)

31 Review terms:

32 Karyotype

33 Homologous Chromosomes: identical chromosomes – one from each parent

34 Chromatid: one of two identical copies of the same DNA

35 Mitosis vs. Meiosis Mitosis -Produces two offspring cells of 2n -One cell division cycle -produces body cells -no chromosomes cross over Meiosis -produces four offspring cells of 1n -two cell division cycles (meiosis I & 2) -produces gametes -chromosomes cross over

36 8 Stages of Meiosis Prophase I Metaphase I Anaphase I Telophase I Prophase II Metaphase II Anaphase II Telophase II Meiosis I Meiosis II

37 Prophase I -Chromatids form -Homologous chromatids pair up to form tetrads

38 Metaphase I -tetrads line up at equatorial plate -Crossing over: breaking off of arms of chromatids and switching places on another homologous chromosome

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40 Anaphase I -tetrads are pulled apart

41 Telophase I -cytokinesis occurs

42 Prophase II

43 Metphase II

44 Anaphase II

45 Telophase II

46 Spermatogenesis: meiosis that produces sperm Produces 4 fertile cells; in humans @ 400 billion

47 Oogenesis: meiosis that produces egg cells Produces 1 fertile cell; about 400 in a lifetime

48 Types of Reproduction 1.Sexual reproduction: offspring are the result of combination of parental genetics 2.Asexual reproduction: no exchange of genetic information – genetically identical to parent

49 Nature protects the female

50

51 Cellular Disorders

52 Cancer: a mitotic disorder

53 Characteristics: 1.Abnormal rates of cell division; uncontrolled 2.Produces malfunctioning cells 3.Kills the organism 4.Lack Density Dependent Inhibition (DDI)

54 Density Dependent Inhibition (DDI) Ability of a cell to “sense” space – ability to stop growth in a restricted space

55 Density Dependent Inhibition (DDI) Lack of DDI – cells continue to divide – causes tumors

56 Types of Tumors 1.Benign: cancer cells remain at the original site 2.Malignant: cancer cells become aggressive and spread throughout the body

57 Metastasis: movement of cancer through the blood/lymph to other organs

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59 Causes: carcinogens and contributing factors

60 -smoking

61 -radiation

62 -virus (HPV)

63 -genetic makeup

64 Treatments

65 -surgical removal

66 -radiation treatment

67 -chemotherapy: taxol, vincristine, vinblastine

68 Cellular Differentiation -begins following fertilization -process by which generic cells gain specific functions -mitosis process

69 Stem Cells: undifferentiated cells that can become any type of cell Stem Cells Skin Cells Neuron (nerves) Bone Cell Muscle Cells Cardiac Muscle

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