2. In Siamese cats, a correlation has been suggested between fur colour, fur softness and voice pitch.
Each trait is determined by a single gene, where brown-black (seal-point) colour is dominant to grey
(blue-point) colour, slick fur is dominant to soft fur, and low-pitch voice is dominant to high-pitched
voice. To determine if gene linkage may be responsible for this correlation, the following cross was
made across a number of different breeders:
Pure-breeding seal-point, slick-fur, high-pitch voice x Pure-breeding blue-point, soft-fur, low-pitch voice
F1 progeny were test-crossed to homozygous recessive individuals and the progeny phenotypes were
pooled from different breeders:
Progeny
Number
phenotype
Seal, slick, high
57
Blue, soft, low
51
Seal, soft, high
19
Blue, slick, low
16
Seal, slick, low
60
Blue, soft, high
54
Seal, soft, low
18
Blue, slick, high
15
290