1 Three recessive genes on chromosome 2 of Drosophila melanogaster are: welt ,
cinnabar , and brown . The numbers of phenotypes from a trihybrid test cross are shown below:
What is the gene order and map distance between the three genes and what is the percent
interference?
Problem 2 Three recessive genes on chromosome 1 of Drosophila melanogaster are: prawny , no
bridge , and cut . The numbers of phenotypes from a trihybrid test cross are shown below:
Wild type 265
welt ,cinnabar ,brow
n
239
brown 155
7
welt ,cinnabar 150
9
cinnabar 859
welt ,brown 829
welt 236
8
brown ,cinnabar 236
5
Wild type 2
prawny ,no
bridge ,cut 10
no bridge 196
prawny ,cut 191
cut 109
prawny ,no bridge 131
prawny
354
4
no bridge ,cut 348
1
What is the gene order and map distance between the three genes and what is the percent
interference?
Problem 3 Three recessive genes on chromosome 3 of Drosophila melanogaster are: claret ,
rough , and ebony . The numbers of phenotypes from a trihybrid test cross are shown below:
What is the gene order and map distance between the three genes and what is the percent
interference?
Problem 4 Three recessive genes on chromosome 2 of Drosophila melanogaster are: brown , welt
, and cinnabar . The numbers of phenotypes from a trihybrid test cross are shown below:
Wild type 90
claret ,rough ,ebon
y
93
claret 824
rough ,ebony 774
ebony 390
claret ,rough 372
rough 261
9
claret ,ebony 259
0
Wild type 597
brown ,welt ,cinnaba
r
629
brown 167
2
welt ,cinnabar 170
2
cinnabar 201
brown ,welt 173
welt 106
1
What is the gene order and map distance between the three genes and what is the percent
interference?
Problem 5 Three recessive genes on chromosome 1 of Drosophila melanogaster are: wider ,
prawny , and no bridge . The numbers of phenotypes from a trihybrid test cross are shown
below:
What is the gene order and map distance between the three genes and what is the percent
interference?
Problem 6 Three recessive genes on chromosome 2 of Drosophila melanogaster are: dachs ,
aristaless , and odd skipped. The numbers of phenotypes from a trihybrid test cross are shown
below:
brown ,cinnabar 107
0
Wild type 332
1
wider ,prawny ,no
bridge
336
5
no bridge 154
wider ,prawny 131
wider 732
prawny ,no bridge 763
prawny 29
wider ,no bridge 21
Wild type 341
dachs ,aristaless ,odd
skipped 288
aristaless 274
9
dachs ,odd skipped 277
9
dachs 66
What is the gene order and map distance between the three genes and what is the percent
interferenc
