In gunea pigs , short har (L) is dominant to long hair (l) and heterozygous conditions of yellow coat (cy) and white coat (Cw) give cream coat. A short-haired, cream guinea pig is bred to a long-haired, white guinea pig, and a long haired , cream baby guinea pig is produced. when the baby grows up it is bred back to the short-haired, cream parent. what phenotypic classes and in what proportions are expected among the offspring?

Question

In gunea pigs , short har (L) is dominant to long hair (l) and heterozygous conditions of yellow coat (cy) and white coat (Cw) give cream coat. A short-haired, cream guinea pig is bred to a long-haired, white guinea pig, and a long haired , cream baby guinea pig is produced. when the baby grows up it is bred back to the short-haired, cream parent. what phenotypic classes and in what proportions are expected among the offspring?

Answer 1

To determine the phenotypic classes and proportions of the offspring, we need to analyze the genotypes of the parent guinea pigs and then use Punnett squares to determine the possible combinations of alleles that can be inherited by the offspring.

Given information:
- Short hair (L) is dominant over long hair (l).
- Yellow coat (cy) and white coat (Cw) are heterozygous conditions that give a cream coat.
- A short-haired, cream guinea pig is bred to a long-haired, white guinea pig, resulting in a long-haired, cream baby guinea pig.

Let's determine the genotypes of the parent guinea pigs:

- Short-haired, cream parent: LLcyCw
- Long-haired, white parent: llcyCw

Now, we can create a Punnett square to determine the possible genotypes and phenotypes of the offspring. We will use the first parent's genotype (LLcyCw) vertically and the second parent's genotype (llcyCw) horizontally:

l l c y C w
L | Ll | Ll | Ll | Ll | Ll | Ll |
L | Ll | Ll | Ll | Ll | Ll | Ll |
c | Llc | Llc | Llc | Llc | Llc | Llc |
y | Lly | Lly | Lly | Lly | Lly | Lly |
C | LC | LC | LC | LC | LC | LC |
w | Lw | Lw | Lw | Lw | Lw | Lw |

From the Punnett square, we can list the different genotypic and phenotypic classes and determine their proportions:

Genotypic classes and respective proportions:
- LLcycw (short hair, cream coat): 4/16 or 25%
- LLcyCw (short hair, cream coat): 4/16 or 25%
- Llcycw (short hair, cream coat): 4/16 or 25%
- LlcyCw (long hair, cream coat): 4/16 or 25%

Phenotypic classes and respective proportions:
- Short hair, cream coat: 8/16 or 50%
- Long hair, cream coat: 4/16 or 25%
- Short hair, white coat: 0/16 or 0%
- Long hair, white coat: 4/16 or 25%

So, among the offspring, we can expect 50% to have short hair and a cream coat, 25% to have long hair and a cream coat, and 25% to have long hair and a white coat.