A heterozygous trihybrid corn plant is test crossed and the following progeny are produced. The mutant traits - booster (b), silkless (s), liguleless (l) - are recessive to their wild-type (+) alternatives. (Hint: The wild-type alternatives (+) for each of the three mutant traits can be named B, S, and L, respectively.)
Three Possible Phenotypes Progeny
booster + + 6
booster silkless + 137
booster silkless liguleless 291
+ + liguleless 142
+ silkless liguleless 3
+ silkless + 30
booster + liguleless 34
+ + + 339
982 = Total Offspring
a) (2 pt) In the left margin next to the phenotypes above, identify the parental types (P), the phenotypes resulting from double crossovers (D), and the phenotypes resulting from single crossovers (S)
b) (2 pt) Which gene (booster, silkless, liguleless) is between the other two on the chromosome? How can you tell?