Myron constructed the pedigree shown below to study the inheritance of a specific trait in his family. a single gene that has two alleles determines whether or not the trait is expressed.

in the pedigree, myron's parents are represented by a circle and square in the top row. the three sons of the parents are represented by squares in the second row. the shaded square represents the son who expresses the trait that myron is studying.

myron's parents are represented in a pedigree by a circle and square in the top row. the three sons of the parents are represented by squares in the second row. the shaded square represents the son who expresses the trait that myron is studying.

the pedigree provides the strongest evidence for which of these conclusions?

a. the trait is harmful, and may be a genetic disorder.
b. the allele for the trait is dominant.
c. the allele for the trait is recessive.
d. only males may express the trait.