You Are Hired
Background information:
December 23, 1972, was the first day of work for a young nurse. It was an unusually busy
night at the hospital and four beautiful babies were born. Five years later, Mr. and Mrs.
Williams were involved in a car accident. Their son. John, was injured but later made a
full recovery. The night of the accident, Mr. and Mrs. Williams found out that John was
not their biological son. You have been hired by the Williams' to locate their biological son.
Through research, you learn that hair texture is controlled by incomplete dominance.
Individuals who are homozygous dominant for hair texture have curly hair (CC).
Individuals who are homozygous recessive have straight hair (cc). Individuals who are
heterozygous have wavy hair (CC). After reviewing your notes, you decide to concentrate
on two key pieces of information:
Mr. Williams is heterozygous for Type B blood and has wavy hair.
Mrs. Williams is homozygous for Type A blood and has straight hair.
The hospital records contain important information about the other children who were
born in the hospital that day:
Baby 1 is heterozygous for Type B blood and has wavy hair.
Baby 2 has Type AB blood and has straight hair.
Baby 3 is heterozygous for Type A blood and has curly hair.
Your instructions: Determine which baby is Mr. and Mrs. Williams' biological son.