7. Effect Area Stained Stain Type Under UV light, distinct fluorescent banded pattern for each chromosome. Chromosome arms; mostly repetitive AT-rich DNA Quinacrine Q-banding Distinct banded pattern for each chromosome; same as Q-banding pattern except single additional band near centromere of chromosomes 1 and 16 Chromosome arms; mostly repetitive AT-rich DNA Giemsa G-banding Reverse banding pattern of that observed with Q- or G-banding Chromosome arms; mostly unique GC-rich DNA Variety of techniques R-banding Largest bands usually on chromosomes 1, 9, 16, and Y; chromosomes 7, 10, and 15 have medium-sized bands; size of C-bands highly variable from person to person Centromere region of each chromosome and distal portion of Y chromosome; highly repetitive, mostly AT-rich DNA Variety of techniques C-banding

8. Non-Banded Karyotype

14. 7 18 Low/High Resolutions Karyotype

16. Normal Karyotype/ Ideogram

17. Q-Banding

18. C-Banding

19. R - Banding

55. A B C D E F O N M L Q P Remember: There are still two normal chromosomes in the cell! = translocation heterozygote

56. Translocation

60. Reciprocal translocation between chr. 22 and chr. 9 9 9 22 22

61. Reciprocal translocation between chr. 22 and chr. 9 9 9 22 22 Chr. 9 segment has an oncogene; when moved, it becomes active

64. Roberstsonian translocations

66. synapsis Three possible disjunctions

68. X X

69. X X X X

70. © 2007 Paul Billiet ODWS Images believed to be in the Public Domain 23 unpaired chromosomes 23 unpaired chromosomes 23 unpaired chromosomes 23 unpaired chromosomes Fertilisation Child Father 23 pairs of chromosomes Sex cells Meiosis Mother 23 pairs of chromosomes 23 pairs of chromosomes

72. Y X X X Fertilisation Possible children Father Sex cells Meiosis Mother XX XY Chance of a girl 50% Chance of a boy 50% © 2007 Paul Billiet ODWS X Y X XX XY X XX XY

74. © 2007 Paul Billiet ODWS HOMOGAMETIC SEX HETEROGAMETIC SEX SEX DETERMINATION Female XX Male XY Presence of Y-chromosome = maleness (mammals and fish) Presence of second X-chromosome = femaleness (Drosophila, the fruit fly) Male ZZ Female ZW Birds, amphibians, reptiles, butterflies, moths. Female XX Male Xo Grasshoppers

76. Mouse Maize © A. Lane Rayburn Image believed to be in the Public Domain

77. © 2007 Paul Billiet ODWS Organism Chromosome numbers Human 46 Chimpanzee 48 House Mouse 40 Maize 20

78. Image believed to be in the Public Domain