In the fruit fly,Drosophila melanogaster,a spineless (no wing bristles)female fly is mated to a male that is claret (dark eyes)and hairless (no thoracic bristles).Phenotypically wild-type F₁ female progeny were mated to fully homozygous (mutant)males,and the following progeny (1000 total)were observed:
$ \begin{array}{lr}\text { Phenotypes } & \text { Number } \ \text { spineless } & 321 \ \text { wild } & 38 \ \text { claret, spineless } & 130 \ \text { claret } & 18 \ \text { claret, hairless } & 309 \ \text { hairless, claret, spineless } & 32 \ \text { hairless } & 140 \ \text { hairless, spineless } & 12\end{array} $

a) Which gene is in the middle?
b) With respect to the three genes mentioned in the problem,what are the genotypes of the homozygous parents used in making the phenotypically wild-type F₁ heterozygote?
c) What are the map distances between the three genes? A correct formula with the values "plugged in" for each distance will be sufficient.
d) What is the coefficient of coincidence? A correct formula with the values "plugged in" will be sufficient.

Question

In the fruit fly,Drosophila melanogaster,a spineless (no wing bristles)female fly is mated to a male that is claret (dark eyes)and hairless (no thoracic bristles).Phenotypically wild-type F₁ female progeny were mated to fully homozygous (mutant)males,and the following progeny (1000 total)were observed:
 $ \begin{array}{lr}\text { Phenotypes } & \text { Number } \ \text { spineless } & 321 \ \text { wild } & 38 \ \text { claret, spineless } & 130 \ \text { claret } & 18 \ \text { claret, hairless } & 309 \ \text { hairless, claret, spineless } & 32 \ \text { hairless } & 140 \ \text { hairless, spineless } & 12\end{array} $

a) Which gene is in the middle?
b) With respect to the three genes mentioned in the problem,what are the genotypes of the homozygous parents used in making the phenotypically wild-type F₁ heterozygote?
c) What are the map distances between the three genes? A correct formula with the values "plugged in" for each distance will be sufficient.
d) What is the coefficient of coincidence? A correct formula with the values "plugged in" will be sufficient.

Quizplus · Accepted Answer

The Answer of In the fruit fly,Drosophila melanogaster,a spineless (no wing bristles)female fly is mated to a male that is claret (dark eyes)and hairless (no thoracic bristles).Phenotypically wild-type F₁ female progeny were mated to fully homozygous (mutant)males,and the following progeny (1000 total)were observed:
 $ \begin{array}{lr}\text { Phenotypes } & \text { Number } \ \text { spineless } & 321 \ \text { wild } & 38 \ \text { claret, spineless } & 130 \ \text { claret } & 18 \ \text { claret, hairless } & 309 \ \text { hairless, claret, spineless } & 32 \ \text { hairless } & 140 \ \text { hairless, spineless } & 12\end{array} $

a) Which gene is in the middle?
b) With respect to the three genes mentioned in the problem,what are the genotypes of the homozygous parents used in making the phenotypically wild-type F₁ heterozygote?
c) What are the map distances between the three genes? A correct formula with the values "plugged in" for each distance will be sufficient.
d) What is the coefficient of coincidence? A correct formula with the values "plugged in" will be sufficient.

In the Fruit Fly,Drosophila Melanogaster,a Spineless (No Wing Bristles)female Fly