Select the WRONG pair from the following

Options

A. 47, XXY - characteristic palm crease
B. trisomy of 21 - retarded mental and physical development
C. phenylketonuria - mental retardation
D. 45, XO - sterility

Answer

To solve the question of selecting the wrong pair from the given options, we need to analyze each pair carefully.

### Step-by-Step Solution:

1. **Understanding the Options**:
We need to identify the pairs given in the options. The question asks us to select the wrong pair, which means we need to find a mismatch between the genetic condition and its description.

2. **Analyzing Option 1**:
- The first option mentions "47, XXY" and "Characteristic palm crease".
- The XXY condition refers to Klinefelter syndrome, where males have an extra X chromosome. The characteristic palm crease is not typically associated with this condition. Thus, this option is indeed incorrect.

3. **Analyzing Option 2**:
- The second option mentions "Trisomy of 21" and "Retarded Mental and Physical Development".
- Trisomy 21 is known as Down syndrome, which is indeed associated with mental and physical developmental delays. This option is correct.

4. **Analyzing Option 3**:
- The third option discusses "Phenylketonuria" (PKU) and its effects.
- PKU is a metabolic disorder that leads to the accumulation of phenylalanine, causing mental retardation if not managed. This description is accurate, making this option correct.

5. **Analyzing Option 4**:
- The fourth option states "45, X" and "Sterility".
- This refers to Turner syndrome, where females typically have a missing X chromosome (45 chromosomes total). This condition is indeed associated with sterility. Therefore, this option is also correct.

6. **Conclusion**:
After analyzing all the options, we find that the first option is the only one that contains a wrong pair. Therefore, the answer to the question is:

**Answer**: Option 1 (47, XXY - Characteristic palm crease)