In human beings, male is 44A+XY and female 44A+XX. Which of the following is sure case of nullisomy?

Options

A. `(22xx2)-2A+XX`
B. `(2xx22)-2A+X`
C. `(2xx22)-2A-Y`
D. `(2xx22)+2A+XX`

Answer

To solve the question regarding nullisomy in humans, let's break down the steps:

### Step-by-Step Solution:

1. **Understanding Chromosomal Composition**:
- In humans, the typical chromosomal composition is 46 chromosomes, which includes 44 autosomes and 2 sex chromosomes (XX for females and XY for males).
- Therefore, the male is represented as 44A + XY and the female as 44A + XX.

2. **Defining Nullisomy**:
- Nullisomy refers to the condition where a pair of chromosomes is completely missing. In terms of chromosome number, this means that there are 2 chromosomes less than the diploid number (2n).
- For humans, the diploid number (2n) is 46, so nullisomy would result in 44 chromosomes (2n - 2).

3. **Analyzing the Options**:
- We need to examine the provided options to identify which one represents a case of nullisomy (44 chromosomes with one pair missing).
- The options typically would be in the format of chromosome counts and sex chromosome combinations.

4. **Evaluating Each Option**:
- **Option 1**: 44A + XX (This indicates a female with 44 autosomes and 2 sex chromosomes. This is a case of nullisomy since it has 44 chromosomes, meaning one pair is missing).
- **Option 2**: 44A + X (This indicates a female with one X chromosome missing. This is not nullisomy since it does not represent a complete pair missing).
- **Option 3**: 44A + Y (This indicates a male with one X chromosome missing. This is also not nullisomy).
- **Option 4**: 46A + XX (This indicates a normal female with no missing chromosomes, hence not a case of nullisomy).

5. **Conclusion**:
- The only option that represents a true case of nullisomy is **Option 1: 44A + XX**.

### Final Answer:
The sure case of nullisomy is **Option 1: 44A + XX**.