Question

Given above is a pedigree chart showing the inheritance of a certain sex-linked trait in humans. Which is the trait traced in the above pedigree chart?

• A. Dominant X-linked
• B. Recessive X-linked
• C. Dominant Y-linked
• D. Recessive Y-linked

Answer 1

The correct option is A Dominant X-linked

• The pedigree is showing that in generation 1, the male is affected and the female is unaffected.
• In generation 2, the females are affected and the males are unaffected. This means the female in generation 1 was a carrier for a particular trait.
• In generation 3, both males and females are affected.

From this information, it can be predicted that the trait is Dominant X-linked because it is appearing in both males and females and occurring in every generation.

So, the correct answer is 'Dominant X-linked'.