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Published byBethanie Hunter Modified over 9 years ago
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1.Write the possible gametes in the following parent: AaBbCc (notice: one allele per gamete for each genes: ABC, Abc, …) 2. Repeat your answer considering the position of the genes on the chromosomes:
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Assort Independently: A and C; B and C Do NOT assort Independently: A and B - they are on the same chromosome. This will affect the ratios between the phenotypes in F2 generation…
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JohnIsabelle Liz Sue Dan Lucy Luke Joshua Phil What is the relationship between: Dan-Sue; Luke-Joshua; Phil-Isabelle; Liz-Dan; Joshua-Sandy? Sandy marriage children
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JohnIsabelle Liz Dan Sue Lucy Luke Joshua Phil Sandy carriersaffected unaffected
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Is the disorder carried by a dominant or recessive allele? Explain your answer, add genotypes Copy the pedigree. (Question 5)
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Is the disorder carried by a dominant or recessive allele? Explain your answer. Copy the pedigree.
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Answer: The disorder is Recessive, since it ‘skipped a generation’. ‘Normal’ parents must be heterozygous carriers.
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Autosomal Vs. Sex-linked Disorders: Sex-linked disorder = Gene is on a sex chromosome (mostly on the X) Autosomal disorder = Gene is on any of the other 1-22 chromosomes. Dominant vs. Recessive Disorders: Dominant disorder = carried by the dominant allele. Recessive disorder = carried by the recessive allele.
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Several Genetic disorders are inherited in genes that are located on the X chromosome. Predict: Who do you expect will show these disorders more often, females or males? Explain. Women are XX, men are Xy
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Sex-linked Inheritance Definition: Sex-linked genes are located on the sex chromosomes, usually on the X chromosome. So, why is this important?
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Dystrophin (Duchenne MS) Clotting Factor (Hemophilia A) Color Receptor (Red/Green)
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“Royal” Disease - Hemophilia
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Adiel (1986-1999)
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46XX46XY FemaleMale A recessive X-linked disorder has a better chance to show in males. Example: Color Blindness. C = normalc = colorblind Cross: 1) X C X c x X C Y 2) X C X C x X c Y x x
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1) X C X c x X C Y x XCXC XCXC XcXc Y XCXcXCXc XCXCXCXC XcYXcY XCYXCY Daughters: 0% color-blind Sons: 50% chance to be color-blind
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2) X C X C x X c Y XCXC XCXC XCXC Y XCXcXCXc XCXcXCXc XCYXCY XCYXCY Daughters: 100% To be a carrier Sons: 0% chance to be color-blind x
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In Conclusion: 1) X-linked Disorders are more common amongst males. Reason:_________________ 2) Can a colorblind man pass the disorder to his son? Answer:___________________ http://www.kcl.ac.uk/teares/gktvc/ vc/lt/colourblindness/plate1.htm
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About Sickle Cell Anemia Caused by a mutation in the gene for Hemoglobin, which delivers oxygen in the blood. Symbols: H A = Normal hemoglobin. H S = Mutated hemoglobin. - The same symbols are used for the corresponding alleles.
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Sickled Red Blood Cells Normal
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Why does this happen? Normal (with Valine) Mutated (with Glutamic Acid)
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Traffic Jams by sickled cells
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Add punnet square for sickle cell with HA and HS, and with corresponding phenotypes.
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Abundance of the S Allele in Malaria- infested regions.
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Normal and Sickle hemoglobin proteins migrate differently in a gel: normal is more negative. What kind of hemoglobins are for each persons 1, 2 and 3? (Alleles: H is normal and H s is sickled)
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In a genetic test of this family, the mutated and normal proteins were analyzed. Is the disease recessive or dominant? Explain. 1.2.3.4. - + A rare unknown disorder causing deafness was found to be common in one family. affected not affected
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Some disorders we learned about are very harmful, even deadly. Why, then, do they still exist in the population?
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