How many types of gametes will be formed by genotype XxYyZZ ?

Options

A. Two
B. Four
C. Six
D. Eight

Answer

To determine how many types of gametes will be formed by the genotype XxYyZZ, we can follow these steps:

### Step 1: Identify the heterozygous alleles
In the given genotype XxYyZZ, we need to identify the alleles that are heterozygous. Heterozygous alleles are those that have two different forms (e.g., Xx and Yy).

- **Xx**: This is heterozygous (X and x).
- **Yy**: This is also heterozygous (Y and y).
- **ZZ**: This is homozygous (only Z).

### Step 2: Count the number of heterozygous pairs
From the genotype XxYyZZ, we see that there are two heterozygous pairs:
- Xx (1 heterozygous pair)
- Yy (1 heterozygous pair)

So, the total number of heterozygous alleles (n) is 2.

### Step 3: Use the formula to calculate the number of gametes
The formula to calculate the number of different types of gametes is:
\[ \text{Number of gametes} = 2^n \]
where n is the number of heterozygous alleles.

Substituting the value of n:
\[ \text{Number of gametes} = 2^2 = 4 \]

### Step 4: List the types of gametes
Now, we will list the types of gametes formed from the genotype XxYyZZ:
1. XYZ
2. XyZ
3. xYZ
4. xyZ

### Final Answer
Thus, the number of types of gametes that will be formed by the genotype XxYyZZ is **4**.

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