Pedigree charts use shaded symbols to show organisms that have a particular trait, such as a defective gene, being traced in the chart. a breeder wants to make a pedigree chart of male horses to avoid breeding males that have a defective gene. what symbol would the horse breeder use to show a male who is affected by a defective gene?

a. shaded circle
b. shaded square
c. unshaded circle
d. unshaded square