If a particular trait is controlled by 2 gene pairs (polygenic), then calculate the total number of phenotypes and genotypes in `F_(2)` generation.

Options

A. 13
B. 8
C. 14
D. 27

Answer

To solve the problem of calculating the total number of phenotypes and genotypes in the F2 generation for a trait controlled by two gene pairs (polygenic inheritance), we can follow these steps:

### Step 1: Identify the number of gene pairs (n)
In this case, we have 2 gene pairs controlling the trait. Therefore, we set \( n = 2 \).

### Step 2: Calculate the number of phenotypes
To calculate the number of phenotypes in polygenic inheritance, we use the formula:
\[ \text{Number of phenotypes} = 2n + 1 \]
Substituting \( n = 2 \):
\[ \text{Number of phenotypes} = 2(2) + 1 = 4 + 1 = 5 \]

### Step 3: Calculate the number of genotypes
To calculate the number of genotypes, we use the formula:
\[ \text{Number of genotypes} = 3^n \]
Substituting \( n = 2 \):
\[ \text{Number of genotypes} = 3^2 = 9 \]

### Step 4: Calculate the total number of phenotypes and genotypes
Now, we can find the total by adding the number of phenotypes and genotypes:
\[ \text{Total} = \text{Number of phenotypes} + \text{Number of genotypes} = 5 + 9 = 14 \]

### Final Answer
The total number of phenotypes and genotypes in the F2 generation is **14**.

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