Sparkly skin is an Xlinked trait in a newly discovered organ

Sparkly skin is an X-linked trait in a newly discovered organism. If the mom is a carrier for sparkly skin and the dad has normal skin, what percent of male offspring will have sparkly skin? A. 0% B. 25% C. 50% D. 75 E. 100 At what stage of the cell cycle would a nondisjunction of chromosome 21 result in n + 1 chromosomes? A. Meiosis I B. Meiosis II c. could be Meiosis I or Meiosis II

Solution

Q7. c.50%

Explanation:

Xs= Sparkly skin allele

X= normal allele

XsX (Mom) x XY (Dad) = XsX (sparkley female), XsY (sparkly male), XX (normal female), XY (normal Male)

Q8.A. Meiosis I

N+1 or trisomy results from nondisjunction during maternal meiosis I.