Lisa learned that blue eye color is a recessive trait and brown eye color is a dominant trait. Lisa and her sister, Sara, both have blue eyes. Her parents, Joan and Greg, both have brown eyes. Lisa drew her family pedigree, beginning with both sets of grandparents. Which of the following statements about Sara and Lisa's%C2%A0pedigree is true? a Eye color is not a hereditary trait, so Lisa and her sister did not inherit their eye color from their parents. b Both parents each have an allele for blue eyes, but it is not expressed. c The grandparents' genes for eye color are not influencing Lisa and her sister's genes for eye color. d Blue eye color is a trait that is expressed in every other generation.
