Three genes with recessive mutant phenotypes are located on the same chromosome
ID: 53550 • Letter: T
Question
Three genes with recessive mutant phenotypes are located on the same chromosome in maize: waxy endosperm (wx), shrunken endosperm (sh), and virescent seedling (v). A plant with all three mutant phenotypes is crossed with a true-breeding, wild-type plant. Resulting F1 plants are then backcrossed to the parental mutant line to produce the following progeny:
Waxy Shurken Virescent Number
wx sh + 89
+ + v 92
+ + + 1482
wx sh v 1475
+ sh + 480
wx + v 477
wx + + 290
+ sh v 282
Explanation / Answer
Waxy Shurken Virescent Number
wx sh + 89
+ + v 92
+ + + 1482
wx sh v 1475
+ sh + 480
wx + v 477
wx + + 290
+ sh v 282
This is because the three genes have recessive phenotypes which are mutant . So the cross between Mutant and True breeding wild progeny due to co-dominance has resulted in the following numbers