Question

Use the information presented below to answer questions 6 - 8. Tay-Sachs disease is a recessive hereditary abnormality causing death within the first few years of life in individuals with the genotype tt. These individuals never reach sexual maturity. Individuals with the genotype T do not become diseased. Abnormally shortened fingers (brachyphalangy) are due to the presence of alleles in the heterozygous condition (Bb) located at a different locus. Geneticists observed that brachyphalangy was conveyed by the dominant allele and has a penetrance of 63%. It was also observed that individuals bearing the genotype bb have fingers of normal length but the homozygous dominant condition BB is always lethal. A normal man, whose brother died at an early age from Tay-Sachs disease but with no family history of

Answer 1

Tь sta.o6 mu - 26. Manis Genotype = Tt66 Woman's Genotype - Tt Bb. t6 TB AB & Prob. of child having both the ть тть тьь түвь Твь disease = tt Bb нь (T16. <ь | TAB. | «вь | - 1/8 o-115 x 0-63 2 o-o18. Prob. of child having no dise е ттье !) - о 125. 4) Тть : (2) ТИБЫ :(1)ТВ : (2) Тев: (1) tt Bb