You have a Drosophila line that is homozygous for autosomal recessive alleles a
ID: 64921 • Letter: Y
Question
You have a Drosophila line that is homozygous for autosomal recessive alleles a and b. You cross females of this line with males homozygous for the corresponding wild-type alleles. You then cross the F1 heterozygous males with their heterozygous sisters. You obtain the following F2 phenotypes (where letters denote recessive phenotypes and pluses denote wild-type phenotypes:
1,400 ++
400 ab
100 a+
100 +b
What is the recombination frequency between a and b? Remember that there is no recombination in male flies. Show your work.
Explanation / Answer
A drosophila line with aabb is crossed with AABB................AABB x aabb
The heterozygotes obtained are................ AaBb.
AaBb males x AaBb females
9:3:3:1 is the mendelian ratio
total flies are: 2000
Recombination frequency = total number of recombinants/ total number of offsprings x 100
Rf= 200/2000 x100 = 20 %
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.