Total number of phenotypes and genotypes in `F_(2)` generation of a trihybrid cross would be -

Options

A. 35
B. 27
C. 8
D. 64

Answer

To solve the question regarding the total number of phenotypes and genotypes in the F2 generation of a trihybrid cross, we can follow these steps:

### Step 1: Understand the Trihybrid Cross
A trihybrid cross involves three different genes, each of which can have two alleles. In this case, we consider all three genes to be heterozygous (e.g., AaBbCc).

### Step 2: Identify the Number of Heterozygous Genes
In a trihybrid cross, the number of heterozygous genes (n) is 3.

### Step 3: Calculate the Number of Genotypes
To find the total number of genotypes in the F2 generation, we use the formula:
\[ \text{Number of Genotypes} = 3^n \]
Substituting \( n = 3 \):
\[ \text{Number of Genotypes} = 3^3 = 27 \]

### Step 4: Calculate the Number of Phenotypes
To find the total number of phenotypes in the F2 generation, we use the formula:
\[ \text{Number of Phenotypes} = 2^n \]
Substituting \( n = 3 \):
\[ \text{Number of Phenotypes} = 2^3 = 8 \]

### Step 5: Calculate the Total Number of Phenotypes and Genotypes
Now, we add the total number of genotypes and phenotypes:
\[ \text{Total} = \text{Number of Genotypes} + \text{Number of Phenotypes} \]
\[ \text{Total} = 27 + 8 = 35 \]

### Conclusion
The total number of phenotypes and genotypes in the F2 generation of a trihybrid cross is **35**.

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