Autosomal Pedigrees

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Autosomal Pedigrees. Catalyst: Incest increases the likelihood of having a child with birth defects. Why do you think this is true?. Write in complete sentences! Don’t talk during the Catalyst!. Big Q s. Why do some children inherit genetic diseases, but other family members do not? - PowerPoint PPT Presentation

Text of Autosomal Pedigrees

  • Autosomal PedigreesCatalyst:Incest increases the likelihood of having a child with birth defects.Why do you think this is true?Write in complete sentences!Dont talk during the Catalyst!

  • Big QsWhy do some children inherit genetic diseases, but other family members do not?What does it means for a disease to skip a generation?What are Huntingtons, Cystic Fibrosis, or Tay Sachs?

  • By the end of today, SWBATDetermine if an autosomal disorder is dominant or recessiveAnalyze autosomal pedigrees to determine the inheritance of disordersObjectives

  • AgendaCatalystPedigrees? Pedigreat!PracticeExit Question

  • Autosomal vs. Sex-LinkedHumans have 23 pairs of chromosomesAutosomes: chromosomes #1-#22Sex chromosomes: chromosome #23 (X or Y)Pedigrees show how traits are inherited across many generations.

  • PedigreesKey Point #1: Symbols show the relationships in a pedigreeParentsChildrenMaleMaleFemaleFemale

  • Unaffected: normal (no disorder)

    Affected: has disorder

    Pedigree SymbolsW MAN

  • What do the symbols mean?

  • Dominant and Recessive DisordersKey Point #2: Autosomal disorders are either dominant or recessive

    Dominant disorderPerson has disease if there is AT LEAST ONE dominant alleleDD = has disorderDd = has disorderdd = no disorder

  • Dominant and Recessive DisordersKey Point #2: Autosomal disorders are either dominant or recessive

    Recessive disorderPerson has disease if there are TWO recessive allelesDD = no disorderDd = carrierdd = has disorder

  • Dominant DisordersKey Point #3: There are two tricks to figuring out if a disease is dominant or recessive.

    If both parents show the disorder but a child does not, the disorder is dominant.

    DD = has disorderDd = has disorderdd = no disorder

  • Recessive DisordersIf both parents do not show the disorder, but a child does, then it is recessive.

    DD = no disorderDd = carrierdd = has disorder

  • Example 2 Ms. S does S, s

  • Example 3 Help me out! H, h

  • Huntingtons Disease

  • How many children did individuals I-1 and I-2 have?How are III-2 and II-4 related? How are I-2 and III-5 related?Which members of the family above are afflicted with Huntingtons Disease?How many girls did II-1 and II-2 have? How many have Huntingtons Disease?There are no carriers for Huntingtons Disease you either have it or you dont. With this in mind, is Huntingtons disease caused by a dominant or recessive trait? Explain how you determined your answer.

  • Cystic Fibrosisand some incest

  • How are individuals III-1 and III-2 related?Is the trait for Cystic Fibrosis dominant or recessive? How do you know?Name 2 individuals that have Cystic Fibrosis. Explain how you determined your answer.Name 2 individuals that were carriers of Cystic Fibrosis. Explain how you determined your answer.

  • Guided PracticeTry the worksheet.

    Skip numbers 4 6. (The paragraphs information is wrong. It is a pedigree for a recessive trait.)

  • Exit QuestionDraw this pedigree, and label the genotype of each individual. (Use B and b)

    Write in complete sentences!Dont talk during the Exit Question!

    Today we are talking about the inheritance of autosomal traits (traits controlled by autosomes). Tomorrow we will talk about the inheritance of sex-linked traits (traits controlled by sex chromosomes).

    *Identify males, females, people with disorder, people without*Huntingtons: cant control body movement, jerk and uncoordinated*Cystic fibrosis: mucus buildup in internal organs, abnormal absorption of nutrients in small intestine (pancreas doesnt produce proper enzymes)*Common misconception is always that you have to look at the FIRST two parents, not ANY parents, to determine dom/recessive. CORRECT THIS!*Common misconception is always that you have to look at the FIRST two parents, not ANY parents, to determine dom/recessive. CORRECT THIS!

    *Think aloud how to solve this pedigree yourself*Think aloud how to solve this pedigree yourself*Affects muscle coordination, cognitive decline and dementia