2. 10-1 Cell Growth Growth and Development!!

3. Reflection 2/25 – Describe what is meant by the cell cycle. 2/26 – Name the 2 types of cells in your body. 2/29 – Name the 4 stages of the cell cycle. 3/1 – Describe what makes your cells divide. When do they know to divide. 3/2 – Explain how chemotherapy works. 3/3 – Name the 4 stages of mitosis and its purpose.

4. Reflection ¾ - Describe what happens in prophase.

5. When Do New Cells Need to Form? A. Growth - More cells B. Maintenance (repair and replacement)--> intestinal lining/RBC’s) C. Asexual reproduction D. Formation of sex cells (Meiosis)

6. Why Can’t Your Cells Grow Forever? 1. Cell membrane cannot control material 2. DNA overload

7. What stops cell from growing? Proximity to neighbor cells. Cells in a petri dish will continue to grow until they come into contact with other cells. Similarily, skin around a wound After a cell has quit growing, it is time to divide!!! Mitosis

8. TOO BIG!: Cell membrane cannot control all movements of materials The larger a cell grows the more trouble it has… moving enough nutrients in Moving all the waste materials out

9. DNA overload!!! DNA overload Your DNA controls all activities in the cell. When the cell gets too big then the DNA cannot control all activites.

10. Cell Cycle – life of a cell The life of a cell. It has a pattern of cell growth, DNA replication, and cell division. Results in two new daughter cells.

11. What’s Missing?

12. M Phase, Cell Division and Mitosis

13. The Cell Cycle - series of events that cells go through as they grow and divide The cell cycle is divided into two halfs Interphase - period of the cell cycle between cell divisions Mitosis phase and cytokinesis – period of time when mitosis and cell division occurs

14. 3 Main Events of a Cell Cycle 1. Interphase G1 - growth S – DNA replication G2 – growth and prepare for division 2. Mitosis Phase – nucleus dividing Prophase Metaphase Anaphase Telophase 3. Cytokinesis – cell division

15. Parts of Interphase G 1 Phase(growth) Cell grows Synthesize new proteins and organelles Doing their jobs Longest phase of cell cycle

16. S Phase S Phase(synthesis) Chromosomes(DNA) are replicated Key proteins associated with replication are made (centromeres

17. Gap 2 Phase G 2 Phase(growth) Shortest of the 3 phases of interphase Organelles and molecules for cell division are produced (centrioles) Check-up phase before mitosis

18. Cell Cycle http://www.cellsalive.com/mitosis.htm http://www.johnkyrk.com/mitosis.html

19. The Cell Cycle The sequence of growth and division of a cell. 95% of cell cycle in interphase(growth) 5% of cell cycle in mitosis(division)

20. G - 0 Stage This is a stage of interphase that SOME cells enter. Cells such as nerve and white blood do not divide often so they enter this stage of rest.

21. Animated Cycle http://www.cellsalive.com/cell_cycle.htm

22. MITOSIS

23. Definitions Histones Telomeres Somatic cells Chromatin Chromosomes Centromeres Spindle fibers

24. Parts of a Chromosome Chromosome: X’s during mitosis. Humans have 46 chromosomes Histones: proteins DNA wraps around. Makes it condensed!!! Chromatin: Loose DNA when it is not condensed during interphase. DNA only condenses during mitosis and meiosis.

25. Centromeres: Center point where chromatids are attached. Spindle Fibers - Fibers that pull part the chromosomes during mitosis.

26. Parts of the Chromosomes Telomere: DNA molecules at the end of the chromosomes that do not code for genes. They keep the DNA from unraveling. Chromatid:One half og the duplicated chromosome. Centromere: Each sister chromatid is held together at the centromere. ALL OF THIS IS FORMED AFTER REPLICATION!!!

27. Some Definitions Haploid cells – Sex cells and have half the number of chromosomes – sex cells Diploid cells – Full number of chromosome – body cells Gamete – Sex cells Somatic Cells – body cells Produced through mitosis Has 46 chromosomes (23 pairs)

28. Parts of the Chromosomes

29. Chromatin condenses in chomosomes before mitosis begins Chromatin - interphase Chromosomes - mitosis

30. Histone

31. Parts of a Chromosome

32. Mitosis Division of the nucleus. Followed by cytokinesis!!! The daughter cells are identical to one another and to the original parent cell.

33. Mitosis Prophase Metaphase Anaphase Telophase

34. Prophase Longest phase of mitosis Chromatin condenses into chromosomes Spindle fibers form and attach to centrioles Nuclear membrane dissappears Nucleolus breaks down

37. Prophase Animal Cell Plant Cell Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

38. Prophase The cell prepares for nuclear division Animal Cell Packages DNA into chromosomes Plant cell Packages DNA into chromosomes

39. Metaphase Centromeres line up across the center of the cell Spindle fibers connect to centromeres

41. Anaphase Chromosomes are pulled apart by spindle into individual chromatids. The chromatids are now considered Chromosomes!!

42. Anaphase Centromeres split Sister chromatids are pulled apart to opposite poles of the cell Each chromatid is now a separate chromosome

44. Telophase Nuclear envelopes (2) and nucleolus reform Chromosomes begin to uncoil Spindle fibers and centriole disappear.

53. Mitosis Animation http://www.cellsalive.com/mitosis.htm

54. Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

55. Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

56. Cytokinesis Cytoplasm divides Two new IDENTICAL daughter cells are now separate

57. Cytokinesis The cytoplasm pinches in half Animal - cleavage furrow Plants - cell plate  http://www.johnkyrk.com/mitosis.html http://www.johnkyrk.com/mitosis.html

58. In plant cells, a cell plate forms. The cell plate is synthesized by the fusion of multiple membrane- bounded vesicles. Their fusion supplies new plasma membrane for each of the two daughter cells. Synthesis of a new cell wall between the daughter cells then occurs at the cell plate.cell wall

59. External and Internal Factors ExternalInternal Cell to cell contactkinase Growth factors –cyclin released when cells touch

60. Cyclins Protein that controls cell division.. They can make cells grow in a petri dish. Doesn’t work on all cells.

61. Controls on Cell Division

62. Apoptosis Cell death. Some factor signals genes to produce self destructive enzymes. Not sure why. EX: webbing of toes on an embryo, tad pole tail, mutated DNA in a cell

63. Cancer Class of disease caused by uncontrolled cell division. Arises when the regulation of the cell cycle breaks down. The cells continue to divide with the absence of internal and external growth factors. Benign tumor: cancer cells remain in one mass and usually can be removed. Malignant: cancer cells break away from the cancer cells to other parts of the body.

64. Why are cancer cells so dangerous? Cancer cells cannot perform the duties needed by the body. Too many cancer cells and the body cannot perform the processes needed to live. A large tumor can apply pressure to other organs and affect the processes of organ.

65. What causes cells to form cancer? Cancer cells comes from regular cells that have damage in one of the two genes that makes the proteins for cell cycle regulation. Oncogene: gene that accelerates the cell cycle. Gene 2 : breaks cell cycle. A mutation in these 2 genes can be inherited or a carcinogen can cause a mutation in these genes.

66. Cancer cells are YOUR OWN CELLS that have cyclins messed up so they continue to divide and do not GROW enough!

67. Causes of Cancer Carcinogen: Substances known to cause the cell cycle genes to mutate and cell divide uncontollably. Various forms of cancer have many causes Smoking Radiation Viral infections The common thread in all cancers is that control over the cell cycle has broken down. Over 50% of cancer cells have a defect in the p53 gene.

68. p53 antioncogene p53 is a tumor suppressor gene found mutated in about half of human cancers. It encodes a gene regulatory protein that is activated by damaged DNA and is involved in blocking further progression of the cell cycle.

69. Treatments for Cancer Radiation and chemotherapy – used to kill the cancer cells and stop division. They kill good and bad cells.

70. Stem Cells Stem cells are a type of body cell that have the ability to 1.Divide and renew themselves 2.Remain undifferentiated 3.Develop into a variety of specialized cells.

72. Defined: Tightly coiled DNA Forms during cell division New chromosomes created for new cells 2 Parts: 1) Chromatids: two identical parts of a chromosome 2) Centromere: Joins chromatids together

73. Defined: Picture of an individuals chromosomes Identify sex & chromosome defects Size of final pair identifies sex Same size: XX = female Different size: XY = male Normal human will have 46 chromosomes

74. Down Syndrome: What’s Wrong? Writing notation: 1 st : total chromosome # 2 nd : Sex chromosomes 3 rd : extra or missing Down Syndrome: 47, XY, +21

75. Turner’s Syndrome: What’s Wrong? Write the notation for Turner’s Syndrome. 45, X, -23 or 45, XO, -23

76. Patau’s Syndrome: What’s Wrong? Write the notation for Patau’s Syndrome. 47, XY, +13

77. Klinefelter’s Syndrome: What’s Wrong? Write the notation for Klinefelter’s Syndrome. 47, XXY, +23

78. Diploid Cells = Cells with the full set of chromosomes Paired chromosomes Half of our chromosomes come from each parent (23 from each parent) Somatic (non-sex) cells are diploid Created by mitosis Ex: Skin, Muscle, Nerve, Blood Cells

79. What is the human diploid chromosome number? Remember…Diploid = total number of chromosomes Answer = 46

80. What is the human somatic chromosome number? Remember…Somatic cells are non-sex cells… …Somatic cells are diploid… …Diploid cells have the full set of chromosomes Answer = 46

81. How many chromosomes are in brain cells? Remember…Brain cells are non-sex cells… …Somatic cells are non-sex cells… …Somatic cells are diploid… …Diploid cells have the full set of chromosomes Answer = 46

82. Haploid Cells = Cells with ½ the total number of chromosomes Gametes (sex cells) are the only haploid cells Ex: Sperm, Egg, Pollen Chromosome number is reduced by meiosis How do humans get 46 chromosomes? Haploid sperm cell (23) + Haploid egg cell (23) = Diploid zygote (46)

83. What is the human haploid chromosome number? Remember…Haploid = half number of chromosomes Answer = 23 chromosomes

84. What is the human gamete chromosome number? Remember…Gamete cells are sex cells… …Sex cells are haploid… …Haploid cells have ½ the set of chromosomes Answer = 23

85. How many chromosomes are in female egg cells? Remember…Egg cells are sex cells… …Sex cells are gametes… …Gamete cells are haploid… …Haploid cells have ½ the set of chromosomes Answer = 23

87. What is the diploid chromosome number? 42

88. What is the haploid chromosome number? 21

89. How many chromosomes would be in somatic cells? 42

90. How many chromosomes would be in brain cells? 42

91. How many chromosomes would be in gamete cells? 21

92. How many chromosomes would be in egg cells? 21

93. How many chromosomes would be in muscle cells? 42

94. How many chromosomes would be in sperm cells? 21

95. Is this a male or female rat? male

96. Quick Review Chromsomes are tightly coiled strands of DNA Diploid (somatic) cells contain the entire set of chromosomes Haploid (gametes) cells contain only ½ the total number of chromosomes

97. Limit of cell size? 1. TOO SMALL - There will not be enough room for all the organelles to carry out the processes needed.

98. Cells Divide at Different Rates The rate of cell division is determined by the body’s need for that type of cell. Nerve cells do not divide because they do not die like our skin cells. A new layer of skin is replaced every 3 weeks. The lining of your intestines has to be replaced often because of the wear and tear. This is also skin cells.