Number of phenotypes possible from AaBbCc `xx` AaBbCc is

Options

A. 16
B. 12
C. 8
D. 4

Answer

To solve the question of how many phenotypes are possible from the cross AaBbCc `xx` AaBbCc, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Number of Gene Pairs**:
In the given cross, we have three pairs of contrasting traits represented by the alleles A, B, and C. Each pair consists of one dominant and one recessive allele (A/a, B/b, C/c).

2. **Count the Gene Pairs (n)**:
Here, we have:
- A/a (1 pair)
- B/b (1 pair)
- C/c (1 pair)
Thus, the total number of gene pairs (n) is 3.

3. **Use the Formula for Phenotypes**:
The formula to calculate the number of phenotypes from a cross involving n pairs of contrasting traits is given by:
\[ \text{Number of phenotypes} = 2^n \]
where n is the number of gene pairs.

4. **Calculate the Number of Phenotypes**:
Plugging in the value of n:
\[ \text{Number of phenotypes} = 2^3 = 8 \]

5. **Conclusion**:
Therefore, the number of phenotypes possible from the cross AaBbCc `xx` AaBbCc is **8**.