For the following;
14. Genetic crosses for coat length in dogs.
- a. Long x Short: 50% long coat, 50% medium length coat.
- b. Medium x Long: 75% long coat, 25% medium length coat.
- c. Short x Medium: 50% medium length coat, 50% short coat.
15. Purebred line and long coat: No, a dog with a long coat cannot be considered a purebred line.
16. Genotypes for Smily eye shapes:
- Starred eyes: SS
- Circular eyes: CC
- Circle with a star: CS
How to determine offspring?
14. Genetic Crosses for Coat Length in Dogs
a. Long x Short
Cross: TT x GG
Genotypic percentages:
50% TT (long coat)
50% TG (medium length coat)
Phenotypic percentages:
50% long coat
50% medium length coat
b. Medium x Long
Cross: TG x TT
Genotypic percentages:
25% TT (long coat)
50% TG (medium length coat)
25% GG (short coat)
Phenotypic percentages:
75% long coat (25% TT + 50% TG)
25% medium length coat (25% TG)
c. Short x Medium
Cross: GG x TG
Genotypic percentages:
50% TG (medium length coat)
50% GG (short coat)
Phenotypic percentages:
50% medium length coat (50% TG)
50% short coat (50% GG)
15. Purebred Line and Long Coat
No, a dog with a long coat cannot be considered a purebred line. A purebred line refers to a population of individuals that share the same genetic makeup for a particular trait. In the case of coat length, a dog with a long coat can have either a homozygous TT genotype or a heterozygous TG genotype. The heterozygous TG genotype produces a medium length coat, so a dog with a long coat could have parents with different coat lengths. Therefore, a dog with a long coat does not necessarily come from a purebred line.
16. Genotypes for Smily Eye Shapes
Starred eyes: SS
Circular eyes: CC
Circle with a star: CS