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

PTC taster

Shape (in Pedigree)

Square

Shaded?

No

1.

2.

3.

4.

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.

10.

13

11.

14.

12.

15.