(show all your works and measure that you answer all questions for part a to par
ID: 174999 • Letter: #
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(show all your works and measure that you answer all questions for part a to part d below. Sorry for long questions, but I give thanks to anyone who can help me)
You are analyzing the following human pedigree Assume that the individual marked with an asterisk does not carry any allele associated with the affected phenotype and that no other mutation spontaneously occurs. Also assume complete penetrance. Use "R or X for the allele associated with the dominant phenotype, "r or X for the allele associated with the recessive phenotype Unaffected female affected female (3 affected male Unaffected maie a) What is the most likely mode of inheritance of this disease? Choose from: autosomal dominant, autosomal recessive, X-linked dominant, X-inked recessive. b) List all possible genotypes of the following individuals in the pedigree. Individuals Genotypes #3 c) What is the probability of Individual A being affected? d) What is the probability of Individual B being affected?Explanation / Answer
a) This is a case of X linked recessive inheritance. Here the male (1) is carrying XrY and the female (2) carrying XX.
This is the only case for which they will have progeny with unaffected males (XY) and carrier females (XXr).
[In X linked recessive inheritance, the mutation is observed in males as they have only one chromosome and only observed in females if they are homozygous for Xr]
b) Genotype for 1: XrY (since it is a x linked recessive inheritance)
Genotype for 3: XXr (a cross between 1: XrY and 2: XX will yield carrier daugthers (3: XXr) and non affected son (XY))
c) Probablity of A being affected and d) Probablity of B being affected
since it is a X linked recessive inheritance, the progeny beetween 3 (XXr) and * (XY) will yield XX, XXr, XrY, XY.
Now in any case the female will be non affected (XX, XXr) and when crossed with an affected male (XrY) to give A and B, there can be 2 scenarios:
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