Making a Pedigree© Copyright NewPath Learning. All Rights Reserved. 94-4429Visit www.newpathlearning.com for Online Learning Resources.What is a Pedigree?A pedigree is a diagram that shows how a genetic trait is inherited through several generations of a family. It can help us predict how phenotypes and genotypes may be passed on to future generations.Parts of a PedigreeThis pedigree shows the inheritance of attached earlobes within a family. Children are shown below their parents. Each generation is numbered with a Roman numeral and displayed horizontally.Circles represent females and squares represent males. Shading shows individuals with the attached earlobe phenotype.The genotype is placed below each individual.Generation IGeneration IIFatherEeeeMothereechild1Eechild2Eechild3attached earlobe(recessive - e)free earlobe(dominant - E)GenerationIGenerationIIFatherMotherchild1child2child3child4(XY)Hemophilia CarrierNormal(X¹X)(X¹X)Hemophilia Carrier(XX)NormalNormal(XY)(X¹Y)Hemophilia Normal Clotting(XX, XY)Hemophilia Carrier(X¹X)Hemophilia(X¹X¹,X¹Y)HemophiliaX¹ X(X¹X X¹Y)X¹ XX¹(X¹XX(X¹X(X¹XX¹X(X¹XX¹X(X¹XX¹¹XX(X(XX XXXXX XXXXXXXXX XXXX(XX,X XXXX ,X XXXX ,,(X(X,X XXXX ,,,,,(,,(,,,,,,XXXXX¹Y)X¹Y)X¹Y)XXXXXXXXXXX¹Y)X¹Y)X¹Y)X Y)XXXXXXX Y)X Y)X Y)))))))XXXXXXXXXXXXXXXXXXX Y)X Y)Y)Y))))XX,X,X)))XXXXXXXX,X,X,,)))Genetic DisordersPedigrees can be created for ordinary traits, such as earlobe attachment, or they can be used to track genetic disorders such as hemophilia or . The pedigree below shows the inheritance of hemophilia, a bleeding disorders in which blood does not clot properly. Hemophilia is also a considered a sex-linked trait because the gene is located on the X chromosome. Since the gene for hemophilia is recessive, and it is rare for women to inherit two copies of altered genes, males exhibit the trait much more frequently than females. Women, however, may be carriers of the disease.Normal ClottingCarriernotpossibleMaleFemaleHemophiliaXXXYX1YX1XX1X1A pedigree is a diagram that shows how a genetic trait is inherited through sssssssssssseeeeeeeeeeeeeeeeevvvvvvvvvvvvvveeeeeeeeeeeeeeeerrrrral generattttttttttttiiiiiiiiiiiiiiiioooooooooooooooonnnnnnnnnnnnnnsssssssssss of aaaaaaaaaaaaaaaaa ffffffffffffffffffaaaaaaaaamiiiiiiiiiiiiiiiiillllllllllllyyyyyyyyyyyyyyyyyyyyyy. It can help us predict how phenotypes and genotypes may be passed on tooooooo fffffffffffffuuuuuuuuuuutttttttttuuuuuuuuuuuuuurrrrrrrrrrrrrrrrreeeeeeeeeeeeeee gggggggggggenerations.This pedigree shows the inheritance of attached earlobes within a family. Children are shown below their parents. Each generation is numbered with a Roman numeral and displayed horizontally.Circles represent females and squaresrepresent males. Shading shows individuals with the attached earlobe phenotype.The genotype is placed below each individual.GGGGGGGGGGGGeeeeeeeeeeeeeeennnnnnnnnnnnnnnnnnnnneeeeeeeeeeeeeeeerrrrrrrrrraaattttttiiioooooooooooooooooooonnnnnnnnnnnnnnnnn IGennnnnnnnnnnnnnnnnnneeeeeeeeeeeeeeeeerrrrrrrrrrrraaaaaaaaaaaaaaaatttttttttion IIIIIIIIIIIIIIIIIIIIIIIIFatherrrEEEEEEEEEEEEEeeeeeeeeeeeeeeeeeeeeeMothereeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeecccccccccccccccccchhhhhhhhhhhhhhhhhhhhiiiiiiiiiiiiillllllllllllddddddddddddddd1111111111111111Eechild2Eechild3aaaaaaaattacccccccccchhhhhhhhhhhhhheeeeeeeeeeeeeedddddddddddd earrrllllllllloooooooooooooobbbbbbbbbbbbbeeeeeeeeeeee(reeeeeeeeecccccccccccccceeeeeeeeeeeeeeeeesssssssssssssssssssiiiiiiiiiivvvvvvvvvvvvvveeeeeeeeeeeeeeee - e)ffffffffffffffrrrrrrrrrreeeeeeeeeeeeeeeeeeeeeeee earlobbbbbbbbbbbbbeeeeeeeeeeeeeeee(dominant - E)))GenerationIGeneratiiiiiiiiiiiiiiioooooooooooooooooonnIIFFaaatttttttttttttttthhhhhhhhhhhhhhhhhheeeeeeeeeeeeeerrrMotherrccccccccccccchhhhhhhhhhhhhhhhiiiiiiiiiiiiiilllllllllllllldddddddddddddd1111111111ccccccccchhhhhhhhhhhhhhiiiiiiiiiillllllllllllllddddddddddddddd22222222222222222222ccccccccccccccccchhhhhhhhhhhhhild333333333333333333child4((XY)HHHHHemmmmmmmmmmmmmmoooooooooppppphilia CarrrrrrrrrrrrrrrrrrrrrrrrrriiiiiiiiiiiiiiieeeeeeeeeeeeeeeerrrrrrrNNNNNNNNNNNNNormmmmmmmmmmmmmmmmmmaaaaaaaaaaaaaalllll(X¹X)((((((((((((((((XXXXXXXXXXXXXXX¹X)HHHHHHHHHHHHHHHHeeeeeeeeeeeeeeemmmmmmmmmmmooopppppppppppppphhhhhhhhhhhhhhhiiiiiiiiiiilllllllliiiia CCCCCCCCCCCCCCCaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrrrrrrrrrriiiiiieeeeerrrrpp(((((((((((((((((XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX))))))))))))NNNNNNNNNNNNNNNNoooooooooooormmmalNNNNNNNNNNNNNNNNNNormal(((((((((((((((XXXXXXXXXXXXXXXXXY)(X¹Y)Hemophilia Normal ClottingNormallll CCCCCCCCloottttingl ttttiNlll CCCCCCCClil(((((((((((((((((((XXXXXXX, XY)HHHHHHHHHHHHHHHHeeeeeeeeeeeeeeeeeemmmmmmmmmmmmmmmmmmmmmmoophhhhhhhhhhhhhhhhhhhiiiiiiiiiiiiiiillllllllllllllllllllliiiiiiiiiiiiiaaaaaaaaaaaaaaaaaa CarrrrrrrrrrrrrriiiiiiiiiiiiiiieeeeeeeeeeeeeeeeeerrrrrrrrrrrrrrrrrrrrrHemmmmmmmmmmmmmmmmmmmooooooooooooopppppppppppppppphilllllliiiiiiiiiaaaaaa CCCCCCarrrrrrrrrrrrrrrrrrrriiiiiieeeeeeeeeerrrrrrrrrrrrrrrrrr((((((XXXXXXXXXXXXXXXXX((((((((((((X(((((((((((((XXXXXXXXXXXXXXXXXXX((((XXXXXXXX(((((((XXXXXXXXXXXXX(((((((XXXXXXXXXX((((((((((((((XXXXXXXXXXXXXXXXXXXXXXX((((XXXXXXXXXXXXXXXXXXXXXX((((((XXXXXXXXXXXXXX(XXXXXXXX((XXXXXXXXXXXXXXXXXX((XXXXXXXXXXXXXXXXX((XXXX(((((((( ¹¹¹¹¹XXXX))))))X))))X)))))XXXXXX)X)X)XXXXXXXXXXX)X)X)X)XXXXXXX)X)X)XXXXXXXXXXXXXXXXXXXXXXXX)X)))XXXXXXXXXXXXXX)))))))))))HemophiliaHhhiiliHhhiil(X¹X¹,X¹Y)HemophiliaX¹ X(X¹X X¹Y)X¹ XX¹(X¹XX(X¹X(X¹XX¹X(X¹XX¹X(X¹XX¹¹XX(X(XX XXXXX XXXXXXXXX XXXX(XX,X XXXX ,X XXXX ,,(X(X,X XXXX ,,,,,(,,(,,,,,,XXXXX¹Y)X¹Y)X¹Y)XXXXXXXXXXX¹Y)X¹Y)X¹Y)X Y)XXXXXXX Y)X Y)X Y)))))))XXXXXXXXXXXXXXXXXXX Y)X Y)Y)Y)))))XX,X,X))))))XXXXXXXX,X,X,,)))Pedigrees can be created for orddddddddddddddddiiiiiiiiiiiiiiiiinnnnnnnnnnnnnnnnaaaaaaaaaaarryy ttttttttttttttrrrrrrrrrrrrrrrrraaaaaaaaaaaaaaaaaiiiiiiiitttttts, suuuuuuuuuucccccccccccccchhhhhhhhhhhhhhhhhh aaaaaassssssssssss eeeeeeeeeeeeaaaaaaaaaaaaaarrrrrrrrrlobe atttaaaaaaaaaaaaccccccccccccchhhhhhhhhhhhhhhhhhhhmmmmmmmmmmmmmmmmmmmmmmmmmeeeeeeeeeeeeeeeent, or they can be used to track genetic disorders such as hemophilia or. TThhhhhhhhhhhhhhhheeeeeeeeeee pppppppedddddddiiiiiiiiiiggggggggggggree beeeeeeeeeellllllllllllllloooooooowwwwwwwwwwwwwwwwwwww shows the inheritance of hemophilia, a bleeding disorders in which blood does nnnnnnnnnnnnooooooooooooooootttttttttttt cccclotttttttttt pppppppppppppppppprrrrrrrrrrrroperrrlllllllllllllyyyyyyyyyyyyyyyyyyyyyyyyyy..... HHHHHHHHHHHHHHHemophhhhhhhhhhhhhhhhiiiiiiiiiiiiiilllllllllllllliiiiiiia is also a considered a sex-linked trait because the gene is locatedddd oooooooooooonnnnnnnnnnnnn tttttttthhhhhhhhhhhhhhhhhhheeeeeeeeeeee XXXXXXXXXXXXXXX ccccccccccchhhhhhhhhhhhhromoooooooossssssssssooooooooooommmmmmmmmmmmmmmmmmmmeeeeeeeeeeeeeeee. Since the gene for hemophilia is recessive, and it is rare for women to inherit two copies of altered genes, males exhibit the trait much more frequently than females. Women, however, may be carriersof the disease.Normal ClottingCarriernotpMaleFemaleHemophilianotpossible1111
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