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:
$\begin{array}{lc}\text { Phenotypes } & \text { Number Observed } \\\hline \text { spineless } & 321 \\\text { wild-type } & 38 \\\text { claret, spineless } & 130 \\\text { claret } & 18 \\\text { claret, hairless } & 309 \\\text { hairless, claret, spineless } & 32 \\\text { hairless } & 140 \\\text { hairless, spineless } & 12\end{array}$
(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 F? heterozygote?
(c)What are the map distances for 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}{lc}\text { Phenotypes } & \text { Number Observed } \\\hline \text { spineless } & 321 \\\text { wild-type } & 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 F? heterozygote?
(c)What are the map distances for 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: $\begin{array}{lc} \text { Phenotypes } & \text { Number Observed } \ \hline \text { spineless } & 321 \ \text { wild-type } & 38 \ \text { claret, spineless } & 130 \ \text { claret } & 18 \ \text { claret, hairless } & 309 \ \text { hairless, claret, spineless } & 32 \ \text { hairless } & 140 \ \text { hairless, spineless } & 12 \end{array}$ (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 F? heterozygote? (c)What are the map distances for 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