Three genes yellow (y) white (w) and cut (ct) are under investigation for possible linkage on the X chromosome. Pure breeding yellow body/white eye/normal wing female flies are crossed with pure breeding black body/red eye/cut wing males. The females in the F1 are black/red/normal, the males are all yellow/white/normal.The F2 males and females are crossed, but ONLY the male flies are are scored (see table). Phenotype Male offspring y + ct 9 + w + 6 y w ct 90 + + + 95 + + ct 424 y w + 376 A. Is the gene order as written (y-w-ct) the same as the gene order on the chromosome? B.What is the mapping distance between yellow and white? C.What is the between cut and white? D.What is the mapping distance between yellow and cut?
Three genes yellow (y) white (w) and cut (ct) are under investigation for possible linkage on the X chromosome. Pure breeding yellow body/white eye/normal wing female flies are crossed with pure breeding black body/red eye/cut wing males. The females in the F1 are black/red/normal, the males are all yellow/white/normal.The F2 males and females are crossed, but ONLY the male flies are are scored (see table).
y + ct 9
+ w + 6
y w ct 90
+ + + 95
+ + ct 424
y w + 376
A. Is the gene order as written (y-w-ct) the same as the gene order on the chromosome?
B.What is the mapping distance between yellow and white?
C.What is the between cut and white?
D.What is the mapping distance between yellow and cut?
If the genes are located on the chromosome then they are classified as linked genes. In this condition the crossing over frequency will be reduced and this crossing over frequency is used to calculate the distance between the genes and their relative position.
Step by step
Solved in 3 steps with 1 images
