Larvae of the silkworm ( Bombyx mori) may display surface patterns called striped and plain. Another pattern is called moricaud, in which the larva is delicately marked with lighter dark lines and dots. Crosses between true-breeding silkworm moths in the three possible combinations yield F1 generations and F2 generations (produced by inbreeding the respective F1 flies) as follows.

Parents F1 F2 Stripedx plain striped 1001 striped: 316 plain Striped x moricaud striped 725 striped : 227 moricaud Plain x moricaud moricaud 1421 moricaud : 443 plain

A. How many genes control this pattern in the larvae?

B. How many alleles does each gene have?

C. Define symbols for the alleles then write the dominance relationships among the alleles.

D. List the possible genotypes for each phenotype using the symbols assigned above: striped Plain Moricaud