The following data are from Bridges and Morgan’s work on the genes black (body color), curved (wings), purple (eye color), speck (black specks on wings) and vestigial (crumpled wings). All 5 genes are on chromosome 2 of Drosophila.

Genes in cross Total progeny Number of Recombinants % recombination
Black, curved 62,679 14,237 23
Black, purple 48,931 3,026 6
Black, speck 685 326 48
Black, vestigial 20,153 3,578 18
Curved, purple 51,136 10,205 20
Curved, speck 10,042 3,037 30
Curved, vestigial 1,720 141 8
Purple, speck 11,985 5,474 46
Purple, vestigial 13,601 1,609 12
Speck, vestigial 2,054 738 36

i.) On the basis of this data, map the chromosome for these 5 genes. Remember that determinations for short distances are more accurate than those for long ones.

ii.) For the first cross in the table, an F1 heterozygous female (for both genes) was testcrossed to a male fly that had a black body and curved wings. The recombinants referred to in the table had either a tan (wildtype)body and curved wings, or a black body and straight (wildtype)wings. Draw the 2 copies of chromosome 2 in the F1
female fly, only with respect to these 2 genes, showing the linkage of the alleles involved.

Answer rating: 100% (QA)

The crosses with recombination ... View the full answer