Directions: Consider a pedigree that is tracking an autosomal recessive trait, where two recessive alleles (tt) result
in the inability to taste a chemical known as PTC. The ability to taste PTC is determined by the presence of a
dominant allele (T). Complete the missing boxes in the chart. The first row has been done for you as an example!
Note: The ability to taste PTC may be more complex than a simple gene trait.
Individual Phenotype
Shaded?
PTC taster
Shape (in Pedigree)
Square
2.
No
1.
3.
4.
5.
6.
Male with genotype TT
Male with genotype Tt
Male with genotype tt
Female with genotype TT
Female with genotype Tt
Female with genotype tt
7.
8.
9.
10.
11.
12.
13.
14.
15.