• ♂ parent appears as C
  • ♀ parent appears as C


  • L offspring = 0.
  • C offspring = 55.

Ferns can have linear sori or circular sori. Assume that these effects are caused by a single gene in which one allele is completely dominant to the other. L refers to linear sori and C refers to circular sori. Note that these letters are different; only one can be used directly as a gene symbol.

Decide upon a gene symbol based on the recessive phenotype (there is not enough information in this question for you to know which is mutant). Define the alleles with a single letter, capitalizing the dominant allele and use lower-case for the recessive.

Assume the ratios fit a standard 1:1, 1:0, or 3:1 ratio and that chance does not make one ratio look like another (i.e. a 3:1 doesn't accidentally fit a 1:1).

If there is not enough information in the data provided to determine which allele is dominant, click the bottom button for more info.

Dominant symbol
Recessive symbol