Question

Which of the following(s) is/are true for X-linked dominant traits?

• A. All daughters of a male who has the trait will also have the trait.
• B. The dominant gene is carried on the X chromosome.
• C. X-linked dominant traits are found only in females.
• D. Sons can have the trait only if their mother also has the trait.

Answer 1

Answer: (A), (B), (D)

The correct options are
A All daughters of a male who has the trait will also have the trait.
B The dominant gene is carried on the X chromosome.
D Sons can have the trait only if their mother also has the trait.

X-linked dominant inheritance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome. 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. So, all daughters of a male who has the trait will also have the trait. For this mode of inheritance, males get their gene for the trait from their mother. So, sons can have the trait only if their mother also has the trait.