Question

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7. Two rare cytological abnormalities were observed in a human male - an extra piece, or satellite on one copy of chromosome 3 and an elongated region on the X chromosome. He is heterozygous for the chromosome 3 abnormality and hemizygous for the X abnormality. What is the probability that his children will inherit both of these two abnormalities? Choose best answer. A) Half of his children will inherit both abnormalities B) Half of the male children and none of the female children will inherit both abnormalities C) Half of the female children and none of the male children will inherit both abnormalities D) One quarter of the female children, and none of the male children will inherit both abnormalities E) One quarter of the male children, and none of the female children will inherit both abnormalities

Answer 1

Rare cytological abnormality observed in male-- Satellite in 3rd autosome--S Extralong X chromosome--X' Male has single allele for both--SsX'Y Female parent is considered normal because it is a rare disease. SsXX SsXX X SsX'Y SX SX' SX' SY SY SX SX SY SY SXSSXXsXX' SxYssXY 50% female with both alleles males do not have both alleles together

50% of the female have both defective alleles together in one organism. No male has both defective alleles together.

Option C is the right option.