The direction of shell coiling in the snail Lymnaea peregra results from a genetic maternal effect. An autosomal allele for a ri
ght-handed, or dextral, shell (s+) is dominant over the allele for a left-handed, or sinistral, shell (s). A pet snail named Martha is sinistral and reproduces only as a female. Which one of the following statements is true? a. Martha's genotype must be SS. T or F
b. Martha's genotype cannot be Ss. T or F
c. At least some of Martha's offspring must be sinistral. T or F
d. Martha's sisters must be sinistral. T or F
