4. b Rod shaped structure Made of a single DNA molecule and proteins called histones –Histones maintain shape of chromosomes –Aids in tight packing of DNA Seen during cell division Coiled and compact

5. DNA and Chromosomes double-stranded DNA molecule

6. centromere homologous chromosomes

7. DNA Replication

8. b Chromosome consists of two identical halves Each half is a chromatid –Formed when DNA makes a copy of itself before cell division –Each new cell will receive one chromatid from each chromosome –Chromatids are held together by a centromere

9. sister chromatids DNA replication

11. 23 pairs Sex chromosomes autosomes

14. Interphase- 75% of cell life cycle G 1 : rapid growth S: DNA replicates; centrioles replicate. G 2 : cell prepares for cell division; microtubular structures form.

15. Cell Division Mitosis: cell divides its nuclear components (chromosomes). Cytokinesis: cell divides its cytoplasmic components.

16. Prophase Metaphase Anaphase Telophase

17. centrioles chromatin plasma membrane nucleolus nuclear envelope

18. lChromosomes shorten and become visible (early prophase) lChromosomes made up of 2 identical chromatin threads called chromatids lCentrioles migrate toward opposite pole pulled by kinetochore lNuclear envelope disintegrates (late prophase).

19. centromere chromosome aster centrioles

20. aster polar fiber chromosomal fiber fragmenting nuclear envelope

21. centrioles nucleus

22. lChromosomes lined up in the middle lMitotic spindle complete.

23. metaphase plate spindle

24. polar fiberschromosomal fibers sister chromatids

25. Chromosome at Metaphase

26. lSister chromatids (= identical strands of DNA) split from each other to form divided identical chromosomes. lKinetochore fibers shorten and pull divided identical chromosomes to opposite sides of the dividing cell. lPolar microtubules slide past each other, lengthening and pushing the cell apart

27. daughter chromosomes

29. lDivided chromosomes reach opposite sides of cell and begin to disperse as chromatin. lNuclear envelopes reforms around separated collections of chromosomes to form two nuclei. lCytokinesis- completion of cell division

30. lSpindle apparatus disintegrates. lCytokinesis usually begins near the end of telophase.

32. lSeparation of cytoplasmic components to yield two daughter cells lMicrofilaments form a contracting ring that pinches the plasma membrane inward between the forming daughter cells

33. cleavage furrow

35. RNA

36. Contrasting RNA with DNA lSingle-stranded lRibose lBases Adenine Uracil Guanine Cytosine lDouble- stranded lDeoxyribose lBases Adenine Thymine Guanine Cytosine RNA DNA

37. mRNA- copies DNA and directs protein synthesis rRNA- joins with ribosomal proteins to make ribosomes tRNA- transfers amino acids to ribosomes to make protein

38. 1.Transcription-occurs in nucleus mRNA copies DNA nucleotide sequence 2. Translation nucleotide sequence in mRNA is uncoded mRNA binds to rRNA tRNA brings appropriate amino acid to mRNA Polypeptide is manufactured

40. DNA Sense Strand mRNA Transcript

41. enzyme mRNA Transcription begins here

42. mRNA

43. anticodon codon tRNA

44. Ribosome Amino Acid tRNA mRNA Codon Anticodon

45. Initiator codon Anticodon AA Binding sites Ribosome mRNA

51. Stop codon AA 1 T A G A U C 2 AA Complete protein

52. Rapid and uncontrollable development and production of cells.

53. 1.Inheritance may increase risk 2.Proto-oncogenes and tumor suppressor genes mutate or become damaged by carcinogens 3.Known carcinogens: Viruses and bacteria Environmental chemicals Tobacco Radiation Dietary factors

54. Conversion begins with a mutation (a change in DNA) by: 1.Chemical 2.Physical 3.Biological Conversion

55. Development and Progression

56. Begins when a chemical substance stimulates growth of a mutated cell Those chemical substances influence a 2 nd stage of carcinogens called promoters. Promoters stimulate cell to divide uncontrollably Metastasis- cancer traveling to other sites; like a forest fire

60. ozone

61. Screens out 99% of harmful UV light Ozone produced by lightening 1% in ozone will result in a 2% in skin cancer Holes in ozone: Dupont- CFCs: hairspray, refrigerators, air conditioning Which country has the highest rate of skin cancer?

62. 1.Avoid sun between 10am to 4pm. 2.Wear sunscreen w/ SPF 40+. 3.Wear appropriate clothing.

63. Genetic testing Biopsy Blood test X-rays, PET, MRI Visual & tactile observation

64. Surgery Radiation Chemotherapy Homeopathy

65. Know family history Get regular medical screenings Learn self-exam techniques Avoid direct sunlight Watch your diet and weight Don’t smoke Drink alcohol in moderation (alcohol decrease heart disease, but increases risk of certain cancers) Become educated

66. INQUIRY 1.What do CFC’s do? 2.What is a proto-oncogene? 3.Name 3 carcinogens. 4.What are the ABCD’s of skin cancer? 5.What is the function of ozone? 6.Who is Henrietta Lacks?

67. INQUIRY 1.Which cells in the body are diploid and which are haploid? 2.During which stage does DNA replication occur? 3.Which stage of mitosis is seen in this picture? 4.At which stage is the cell binuclear? 5.In which phase do chromosomes line up in the center of the cell? 6.Where does the kinetochore attach?