AP Biologymediummcq1 pt
A carrier mother (XᴮXᵇ) and an unaffected father (XᴮY) have children. What fraction of SONS will be affected by the X-linked recessive trait?
A.1/2
B.1/4
C.0
D.All sons
Explanation
Core Concept
Sons receive their mother's X at random: half get Xᴮ (unaffected), half get Xᵇ (affected). The father's Y carries no copy of the gene.
Correct Answer
A1/2
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