All of the following are haploid with 23 chromosomes except

Options

A. First polar body
B. Second polar body
C. Primary oocyte
D. Secondary oocyte

Answer

To solve the question "All of the following are haploid with 23 chromosomes except," we need to analyze the options provided and understand the chromosomal content of each type of cell mentioned.

### Step-by-Step Solution:

1. **Understand the Terms**:
- **Haploid (n)**: A cell with one complete set of chromosomes. In humans, haploid cells have 23 chromosomes.
- **Diploid (2n)**: A cell with two complete sets of chromosomes. In humans, diploid cells have 46 chromosomes.

2. **Identify the Options**:
- **First Polar Body**
- **Second Polar Body**
- **Primary Oocyte**
- **Secondary Oocyte**

3. **Analyze Each Option**:
- **First Polar Body**: Formed during oogenesis, it is haploid and contains 23 chromosomes.
- **Second Polar Body**: Also formed during oogenesis, it is haploid and contains 23 chromosomes.
- **Primary Oocyte**: This is formed from the oogonium and is diploid, containing 46 chromosomes.
- **Secondary Oocyte**: Formed from the primary oocyte, it is haploid and contains 23 chromosomes.

4. **Determine the Exception**:
- The primary oocyte is the only cell listed that is diploid (2n), containing 46 chromosomes. All other options are haploid (n) with 23 chromosomes.

5. **Conclusion**:
- The answer to the question is **Primary Oocyte**, as it is not haploid and does not have 23 chromosomes.

### Final Answer:
**Primary Oocyte** is the exception as it is diploid with 46 chromosomes.

---