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, let's break down the genotypes and perform a Punnett square analysis for each breeding scenario.

1. Breeding between a short-haired, cream guinea pig (LLCwCy) and a long-haired, white guinea pig (llCwCw):

The genotype of the short-haired parent can be written as Llcwcy, while the genotype of the long-haired parent is llCwCw.

To determine the possible genotypes of the offspring, we need to perform a Punnett square analysis:

| Ll | Ll | ll
---|-------|-------|-------
l | Ll,ll | Ll,ll | ll,ll
l | Ll,ll | Ll,ll | ll,ll

The resulting phenotypes and their proportions are as follows:
- Short-haired, cream coat (LlCwCy): 4/4 or 100% probability

2. Breeding between a long-haired, cream guinea pig (llCwCy) and a short-haired, cream guinea pig (LlCwCy):

Both parents have the same genotype, llCwCy.

Again, we'll perform a Punnett square analysis:

| ll
---|-------
L | ll,ll

The resulting phenotype and proportion are:
- Long-haired, cream coat (llCwCy): 1/1 or 100% probability

In summary, when the long-haired, cream baby guinea pig is bred back to the short-haired, cream parent, all the offspring are expected to have a long-haired, cream coat phenotype.

Answer 2

To determine the expected phenotypic classes and proportions among the offspring, we need to apply Mendelian genetics principles. Let's break down the information provided and determine the genetic makeup of the parent guinea pigs involved.

We are given the following information:

- Short hair (L) is dominant to long hair (l).
- The heterozygous condition of yellow coat (cy) and white coat (Cw) results in a cream coat phenotype.

Now let's determine the genetic makeup of the parent guinea pigs involved in the breeding:

1. Short-haired, cream guinea pig:
Genotype: LcyCw

2. Long-haired, white guinea pig:
Genotype: lCwCw

Now, to determine the possible phenotypic classes and their proportions among the offspring, we need to cross the genetic makeup of the parent guinea pigs.

Crossing the first parent (LcyCw) with the second parent (lCwCw), we get the following Punnett square:

| lCw | CwCw
---------------------------------
LcyCw | LlCw | LlCw
LcyCw | lCwCw | lCwCw

From the Punnett square, we can see that there are 4 possible genotypic combinations:

1. LlCw - Short hair, cream coat
2. LlCw - Short hair, cream coat
3. lCwCw - Long hair, white coat
4. lCwCw - Long hair, white coat

The phenotypic classes among the offspring are short hair, cream coat (LlCw) and long hair, white coat (lCwCw).

The proportions would depend on the genotypes of the parents. Since the first parent (LcyCw) is short-haired and cream, and the second parent (lCwCw) is long-haired and white, all the offspring would be heterozygous for both traits (LlCw). Therefore, all the offspring are expected to have a short hair and a cream coat.

So, all the offspring are expected to have a short hair and cream coat phenotype.