Question

which symbol is used to label a male that expresses a sex-linked disorder on a pedigree?

Explanation:

Identify standard pedigree shapes

In standard pedigree charts, circles represent females and squares represent males.

Identify standard pedigree shading

An unshaded shape represents an unaffected individual, a half-shaded shape represents a heterozygous carrier, and a fully shaded shape represents an affected individual who expresses the trait or disorder.

Determine the correct symbol

A male expressing a sex-linked disorder is represented by a fully shaded square.

Answer:

• (A) Unshaded circle
• (B) Half-shaded circle
• (C) Unshaded square
• (D) Shaded square (Correct answer)