There are nine coat colors known in foxes. If a red fox were crossed with a double-black fox, all the hybrids would be red above and black below in a pattern known as a blended cross. If two blended crosses were mated, the
F2 ratio would be as follows: 1 red, 2 smokey red, 2 cross red, 4 blended cross, 1 standard silver, 2 substandard silver, 1 Alaskan silver, 2 sub-Alaskan silver, and 1 double-black.
| (a) | Using the letters A/a and B/b to serve as the genes for these animals, develop a genotype for each variety listed. |
| (b) | Two crosses will produce all blended-cross offspring. One is used above (red fox ´ double-black); what is the other? |
| (c) | List the genotype and phenotype of all the pure-breeding foxes. |
| (d) | Give the genotypic and phenotypic ratio of a cross between two substandard silvers. |
| (e) | Give the genotype and phenotype of the offspring produced in a cross of 1 sub-Alaskan silver and a cross red. |
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Reindeer fur coat
Black Locust
Evaporation of a Black Hole
Rashid Johnson, Souls of Black Folk.
Analysis of double-mutant phenotypes to find order of genes in developmental pathways