A geneticist is mapping the chromosomes of a new fish species. These fish have genes for the dominant traits non- bioluminescent (B), ventral eyes (D), and short spikes (L) with corresponding recessive traits bioluminescent (b), dorsal eyes (d), and long spikes (l). He test- crosses one of these fish who is dominant at all th loci to determine if the three genes are linked resulting in the data shown below: $\frac{(345-125)^{2}}{125}+\frac{(355-215)^{2}}{125}+\frac{(42-125)^{2}}{125}+\frac{(38-125)^{2}}{125}+\frac{(105-125)^{2}}{125}$
$+\frac{(95-125)^{2}}{125}+\frac{(9-125)^{2}}{125}+\frac{(11-125)^{2}}{125}=1148$
a) Why are these data consistent with genetic linkage among the three genes?
b) Perform a chi- square test to determine if these data show significant deviation from the expected phenotype distribution.
c) Determine the recombination frequencies between each pair of genes.
d) Determine the coefficient of coincidence (COC) and interference (I) values for this data set.

Question

A geneticist is mapping the chromosomes of a new fish species. These fish have genes for the dominant traits non- bioluminescent (B), ventral eyes (D), and short spikes (L) with corresponding recessive traits bioluminescent (b), dorsal eyes (d), and long spikes (l). He test- crosses one of these fish who is dominant at all th loci to determine if the three genes are linked resulting in the data shown below: $\frac{(345-125)^{2}}{125}+\frac{(355-215)^{2}}{125}+\frac{(42-125)^{2}}{125}+\frac{(38-125)^{2}}{125}+\frac{(105-125)^{2}}{125}$
$+\frac{(95-125)^{2}}{125}+\frac{(9-125)^{2}}{125}+\frac{(11-125)^{2}}{125}=1148$
 a) Why are these data consistent with genetic linkage among the three genes?
b) Perform a chi- square test to determine if these data show significant deviation from the expected phenotype distribution.
c) Determine the recombination frequencies between each pair of genes.
d) Determine the coefficient of coincidence (COC) and interference (I) values for this data set.

Quizplus · Accepted Answer

The Answer of A geneticist is mapping the chromosomes of a new fish species. These fish have genes for the dominant traits non- bioluminescent (B), ventral eyes (D), and short spikes (L) with corresponding recessive traits bioluminescent (b), dorsal eyes (d), and long spikes (l). He test- crosses one of these fish who is dominant at all th loci to determine if the three genes are linked resulting in the data shown below: $\frac{(345-125)^{2}}{125}+\frac{(355-215)^{2}}{125}+\frac{(42-125)^{2}}{125}+\frac{(38-125)^{2}}{125}+\frac{(105-125)^{2}}{125}$
$+\frac{(95-125)^{2}}{125}+\frac{(9-125)^{2}}{125}+\frac{(11-125)^{2}}{125}=1148$
 a) Why are these data consistent with genetic linkage among the three genes?
b) Perform a chi- square test to determine if these data show significant deviation from the expected phenotype distribution.
c) Determine the recombination frequencies between each pair of genes.
d) Determine the coefficient of coincidence (COC) and interference (I) values for this data set.