What will be the genotypes of parents whose offsprings have equal percentage of four phenotypes ?

Options

A. AaBBCCdd`xx` aabbCCdd
B. AABBCC `xx` AaBbCc
C. AaBbCCDD `xx` aabbCCDD
D. AaBbCcDd `xx` AaBbCcDD

Answer

To determine the genotypes of parents whose offspring exhibit equal percentages of four phenotypes, we can follow these steps:

### Step 1: Understand the Phenotypic Ratio
To achieve equal percentages of four phenotypes in the offspring, we need to consider a dihybrid cross involving two traits, where each trait has two alleles. The expected phenotypic ratio for a dihybrid cross is typically 9:3:3:1, but to get equal percentages of four phenotypes, we need to consider a different approach.

### Step 2: Identify the Required Genotypes
To achieve four equal phenotypes (1:1:1:1), we can use a test cross involving two heterozygous parents. For example, if we consider two traits (A/a and B/b), the genotypes of the parents can be AaBb x aabb.

### Step 3: Perform the Cross
1. **Parent 1 (P1)**: AaBb (heterozygous for both traits)
2. **Parent 2 (P2)**: aabb (homozygous recessive for both traits)

### Step 4: Determine Gametes
- From Parent 1 (AaBb), the possible gametes are:
- AB
- Ab
- aB
- ab

- From Parent 2 (aabb), the only gamete is:
- ab

### Step 5: Create a Punnett Square
Now, we can set up a Punnett square to visualize the offspring:
```
ab
__________
| AB | Ab | aB | ab |
|____|____|____|____|
| AaBb | Aabb | aaBb | aabb |
```

### Step 6: Analyze the Offspring
The offspring genotypes from this cross will be:
1. AaBb (phenotype 1)
2. Aabb (phenotype 2)
3. aaBb (phenotype 3)
4. aabb (phenotype 4)

### Step 7: Determine the Phenotypic Ratio
Each phenotype appears in equal proportions (1:1:1:1), confirming that the genotypes of the parents (AaBb and aabb) will yield offspring with equal percentages of four phenotypes.

### Conclusion
The genotypes of the parents whose offspring have equal percentages of four phenotypes are:
- Parent 1: AaBb
- Parent 2: aabb

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