Miniature wings in Drosophila result from a recessive, sex linked mutation; whil
ID: 45994 • Letter: M
Question
Miniature wings in Drosophila result from a recessive, sex linked mutation; while sepia eyes result from an autosomal, recessive mutation. Wild type phenotypes are normal wings and red eyes respectively.
A female fly that has miniature wings & sepia eyes is crossed with a male that has normal wings & is true breeding for red eyes. F1 are intercrossed to produce F2. Give the phenotypes & phenotypic ratios of F1 and F2 progeny.
A female fly with sepia eyes that is true breeding for normal wings is crossed with a male that has miniature wings and is true breeding for red eyes. F1 are intercrossed to produce F2. Give the phenotypes & phenotypic ratios of F1 and F2 progeny.
Explanation / Answer
A.) Phenotypes & phenotypic ratios of F1 and F2 progeny
F1: all males
wings >> miniature and eyes >> red
F1: all Females
wings >> long wings and eyes >> red eyes.
F2: Male
1/16 male >> miniature >> sepia
1/16 male >> normal >> sepia
normal >> red >>3/16 male
3/16 male >> miniature >> red
F2 : Female
1/16 female >> miniature >> sepia
1/16 female >> normal >> sepia
miniature >> red >> 3/16 female
3/16 female >> normal >> red
B.) Phenotypes & phenotypic ratios of F1 and F2 progeny
F1: all females
wings long and eyes red
F1: all males
long wings and red eyes
F2: males
3/16 males, long wings >> red eyes
long wings >> sepia eyes >> 1/16 males
mini wings >> red eyes >> 3/16 males
mini wings >> sepia eyes >> 1/16 males
F2 : Females
long wings >> red eyes>> 3/8 females
long wings >> sepia eyes>>1/8 females