This tutorial will take you step-by-step through the question. Shell coiling of the snail Lymnaea peregra results from a genetic maternal effect. An autosomal allele for a right-handed shell, s + , called dextral, is dominant over the allele for a left-handed shell, s , called sinistral. In general, snails are hermaphroditic and reproduce as both males and females. However, a pet snail named Martha is sinistral and reproduces only as a female. Martha and her family are shown in the pedigree. Now you can use the step-by-step method to answer this challenging question. From the pedigree, determine Martha's, her mother's, and her father's genotypes. Place the genotypes next to the individuals..