Final answer:
In a cross between two heterozygous curly haired guinea pigs, the expected genotypic ratio is 1 CC:2 Cc:1 cc, resulting in a phenotypic ratio of 3 curly haired:1 straight haired.
Step-by-step explanation:
When two heterozygous curly haired guinea pigs are crossed, we can determine the possible genotypes and phenotypes for their offspring by using a Punnett square. The genotypes will be as follows:
- CC - Curly haired (homozygous dominant)
- Cc - Curly haired (heterozygous)
- cc - Straight haired (homozygous recessive)
The phenotypic ratio will be 3 curly haired:1 straight haired (representing 3 dominant phenotype to 1 recessive phenotype).
Curly hair is dominant, so both CC and Cc will exhibit curly hair, while cc will have straight hair, which is the recessive trait. According to Mendelian genetics, when both parents are Cc (heterozygous), the genotypic ratio in the offspring is expected to be 1 CC:2 Cc:1 cc.