Question

(06.03 mc)

sickle cell anemia is known to run in a family. a pedigree chart for this family is shown below.

what best describes offspring 4?

a female carrier of the disease
a female having the disease
a male carrier of the disease
a male having the disease

Explanation:

Identify pedigree symbols

In standard pedigree charts, shapes represent biological sex:

• Circles represent females.
• Squares represent males.

Offspring 4 is represented by a square, which means this individual is male.

Analyze shading patterns

Shading in a pedigree indicates the phenotype or carrier status:

• Fully shaded shapes represent individuals who have the genetic condition (affected).
• Half-shaded shapes represent heterozygous individuals who are carriers of the gene but do not show symptoms.
• Unshaded shapes represent unaffected, non-carrier individuals.

Offspring 4 is represented by a fully shaded square.

Determine offspring status

Since offspring 4 is a fully shaded square:

• The square shape indicates he is male.
• The full shading indicates he has the disease (sickle cell anemia).

Therefore, offspring 4 is best described as a male having the disease.

Answer:

• A female carrier of the disease
• A female having the disease
• A male carrier of the disease
• A male having the disease (Correct answer)