Study of the eating habits of nightcrawlers revealed the following linkage map:
ID: 52876 • Letter: S
Question
Study of the eating habits of nightcrawlers revealed the following linkage map:
Worm Size Hunger Eating Speed
Normal Normal Slow Dominant
Dwarf Very Hungry Fast Recessive
3 m.u. 6 m.u.
The following crosses were made:
True Breeding strain of Normal Size, Normal Hunger, and Fast Eating worms crossed to
True Breeding strain of Dwarf Size, Very Hungry, and Slow Eating worms. The resulting F1 was then testcrossed.
a. The genotype for the F1 individuals is: (Assign above and below the two chromosomes below:
b. The expected frequency of Normal Size, Normal Hunger, and Slow eating individuals from the testcross is_______________.
c. The expected frequency of Dwarf Size, Fast Eating individuals is________________.
Explanation / Answer
A.Genotype of F1 individual: Let say parent is NNHHFFXnnhhff
Normal Size, Normal Hunger, and Fast Eating worms(NNHHFF)
Dwarf Size, Very Hungry, and Slow Eating worms(nnhhff)
therefore genotype of F1 will be: NnHhFf
B.Test cross: F1 crossed with Recessive parent id test cross.so, NnHhFfXnnhhff
NHF
NHf
NhF
Nhf
nHF
nHf
nhF
nhf
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
results:
from the above test cross: The expected frequency of Normal Size, Normal Hunger, and Slow eating individuals(Atleast one N, H, F in genotype) from the testcross is 8/64=1/8.
C. The expected frequency of Dwarf Size, Fast Eating individuals(having hh andf ff in genotype) is 16/64=1/4
NHF
NHf
NhF
Nhf
nHF
nHf
nhF
nhf
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff
nhf
NnHhFf
NnHhff
NnhhFf
Nnhhff
nnHhFf
nnHhff
nnhhFf
Nnhhff