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  #1  
Old 06-06-2013
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Default genetics

man with tyrosinase negative albinism(chr11) maried with woman with tyrosinase positive albinism(chr15).what is the probability that first child will be affected by albinism?
A 0%
B 25%
C 50%
D 75%
E 100%
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  #2  
Old 06-06-2013
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0%
Both are AR diseases and require both parents to be carrier so 0%
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Old 06-06-2013
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What does negative mean? Phenotype is negative or genotype? It could be 50% if the dad is a hetero with one affected ?
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Old 06-06-2013
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Negative is for enzyme ,.... So tyrosinase neg : no tyrosinase.... Not related to genotype or phentype. Its an ex of locus heterogenicity: same phenotype with mutations in diff genotype
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Old 06-06-2013
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Quote:
Originally Posted by aman_j View Post
Negative is for enzyme ,.... So tyrosinase neg : no tyrosinase.... Not related to genotype or phentype. Its an ex of locus heterogenicity: same phenotype with mutations in diff genotype

So what is causing the albinism in the mother ( tyrosinase positve) then?
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Old 06-06-2013
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No clue ask google
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Old 06-06-2013
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ok fellas
because woman has AR on chr 15 ( 2 mutant copies) and man has AR on chr 11(2 mutant copies) the child will inherit 1 copy of chr 15 from mother (mutant) and another copy of chr 15 from father (normal ),also -1 copy of chr 11 from mother (normal) and another copy of chr 11 from father (mutant) .So child has 1 normal and 1 mutant copy of chr 15 and 1 normal and 1 mutant copy of chr 11,disease is AR and there is 0% of probability that child will be affected
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Old 06-06-2013
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Quote:
Originally Posted by aman_j View Post
No clue ask google
Google has not convinced me yet.
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Old 06-07-2013
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Quote:
Originally Posted by irakly View Post
ok fellas
because woman has AR on chr 15 ( 2 mutant copies) and man has AR on chr 11(2 mutant copies) the child will inherit 1 copy of chr 15 from mother (mutant) and another copy of chr 15 from father (normal ),also -1 copy of chr 11 from mother (normal) and another copy of chr 11 from father (mutant) .So child has 1 normal and 1 mutant copy of chr 15 and 1 normal and 1 mutant copy of chr 11,disease is AR and there is 0% of probability that child will be affected
Ok thanks! Was going for 0% but my explanation was different.
I was thinking the mother has tyrosinase but probably "something" went wrong and made her albino and so shd not pass that on to child. Making it affected man marrying unaffected woman so zero chance of child getting disease.
Well, I would have gotten the answer with poor explanation
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