Practice question

When both body color and eye color genes reside on X chromosome, inheritance pattern becomes sex-linked dihybrid with linkage on same chromosome. Females have two X chromosomes that can recombine during meiosis, generating recombinant X gametes; males have single X transmitted intact to daughters. Consequently joint segregation shows association with sex and parental origin, unlike autosomal dihybrid where both sexes identical. Mapping distance between X-linked genes estimated from recombinant frequency in female progeny only. This pattern excludes autosomal dihybrid, Y-linked, or cytoplasmic inheritance models.