An albino (autosomal, recessive) female with normal vision and phenotypically no

Question

An albino (autosomal, recessive) female with normal vision and phenotypically normal parents has a non-albino brother who is colorblind (X-linked, recessive). She marries a phenotypically normal male. What is the probability their child will be phenotypically normal? Part I: What is the probability that the female is a carrier for colorblindness? Part II: If the female IS a carrier for colorblindness, what is her complete genotype (including albinism)? Part III: If the female IS a carrier, and she and the male have a child together, what is the probability that it will be phenotypically normal? Part IV: What is the overall probability that the child will be phenotypically normal?

Explanation / Answer

And the male is phenotypically normal, let us assume that his genotype is, AA XY.

PART 1: The female had a colour-blind brother, means her mother is carrier (phenotypically normal). Thus, she has 50% chances to inherit the defective colour-blind allele.

PART II: The genotype of an albino (autosomal, recessive) female with normal vision and phenotypically normal parents and a color blind brother is, aa XcX (assuming that she is a carrier for colour blind allele).

PART III: If she had a male child, he will have ½*1/2 = ¼ or 25% chances of inheriting the colour-blind allele.

Part IV: The overall probability that the child will be phenotypically normal is, 75% (25% chances of being colour blind)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.