AP BIOLOGY

Detailed explanation-1: -The abnormal gene dominates the gene pair. For an X-linked dominant disorder: If the father carries the abnormal X gene, all of his daughters will inherit the disease and none of his sons will have the disease. That is because daughters always inherit their father’s X chromosome.

Detailed explanation-2: -In males (who only have one X chromosome), a mutation in the copy of the gene on the single X chromosome causes the condition. Fathers cannot pass X-linked dominant conditions to their sons, but all daughters of affected fathers will be affected with the condition and can pass it on to their children.

Detailed explanation-3: -Sons will be affected if they inherit the mutated X-linked gene from their mother. Fathers cannot pass X-linked recessive conditions to their sons.

Detailed explanation-4: -If the father passes on an X chromosome, the baby will be genetically female, and if the father passes on a Y chromosome, the baby will be genetically male.

Detailed explanation-5: -Remember: The father passes his X sex chromosome (and all its genes) to his daughters and his Y sex chromosome (with its genes) to his sons. Genes act in pairs, one from each parent for the females. For this mode of inheritance, males get their gene for the trait from their mother.