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Why do **X-linked recessive** disorders (haemophilia, red-green colour blindness) appear far more frequently in males than females?
AMales have stronger expression of all X-linked genes
BMales have only one X chromosome, so a single recessive allele expresses
CY chromosome carries dominant suppressors of these diseases
DFemales do not inherit X-linked diseases
Answer & Solution
Correct answer: B. Males have only one X chromosome, so a single recessive allele expresses
Females (XX) need two recessive alleles to express; one recessive plus one dominant makes them silent carriers. Males (XY) have only one X — a single X-linked recessive allele expresses fully, since Y carries no corresponding dominant allele to mask it.
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