Two parents having two loci incompletely linked and heterozygous in nature are crossed. What would be the distribution of phenotypic feature in the `F_2` generation ?

Options

A. Only parental phenotype
B. Only recombinant phenotype
C. High parental and low recombinant phenotype
D. Low parental and high recombinant phenotype

Answer

To solve the question regarding the distribution of phenotypic features in the F2 generation from two parents with incompletely linked loci that are heterozygous, we can follow these steps:

### Step 1: Understand the Genotypes of the Parents
The two parents are heterozygous for two loci, which can be represented as:
- Parent 1: AABB (where A and B are dominant alleles)
- Parent 2: aabb (where a and b are recessive alleles)

### Step 2: Determine the Gametes Produced by Each Parent
Since both parents are heterozygous, they can produce the following gametes:
- Parent 1 (AABB): Can produce gametes AB and ab
- Parent 2 (aabb): Can produce gametes ab

### Step 3: Perform the F1 Generation Cross
When the two parents are crossed, the F1 generation will all be heterozygous:
- F1 Generation: AaBb

### Step 4: Analyze the F2 Generation
To find the F2 generation, we need to cross the F1 individuals (AaBb x AaBb). The possible gametes from each F1 individual are:
- Gametes: AB, Ab, aB, ab

### Step 5: Set Up a Punnett Square
Using a Punnett square, we can determine the combinations of these gametes:
```
AB Ab aB ab
--------------------------------
AB | AABB | AABb | AaBB | AaBb |
--------------------------------
Ab | AABb | AAbb | AaBb | Aabb |
--------------------------------
aB | AaBB | AaBb | aaBB | aaBb |
--------------------------------
ab | AaBb | Aabb | aaBb | aabb |
```

### Step 6: Count the Phenotypes
Now we can count the phenotypes based on the combinations:
- Parental types (AABB, AAbb, aaBB, aabb): 4
- Recombinant types (AABb, AaBB, AaBb, Aabb, aaBb): 6

### Step 7: Determine the Phenotypic Ratio
In the F2 generation, we expect a higher number of parental phenotypes compared to recombinant phenotypes due to the incomplete linkage:
- Parental phenotypes: 4
- Recombinant phenotypes: 6

### Conclusion
The distribution of phenotypic features in the F2 generation will show a higher frequency of parental phenotypes compared to recombinant phenotypes due to the incomplete linkage of the genes.