In a human cell 2.2 meter long thread of DNA distributed in :-

Options

A. one chromosome
B. 23 chromosome
C. X chromosome
D. 46 chromosome

Answer

### Step-by-Step Solution:

1. **Understanding DNA Length in Human Cells**:
- In a human cell, the total length of DNA is approximately 2.2 meters. This length is the result of the DNA contained in all the chromosomes present in the cell.

2. **Chromosome Count**:
- Human cells are diploid, meaning they contain two sets of chromosomes. In total, humans have 46 chromosomes (23 pairs).

3. **Distribution of DNA**:
- The 2.2 meters of DNA is not found in one single strand but is distributed across all 46 chromosomes. Each chromosome contains a specific segment of this DNA.

4. **Base Pairs and Length Calculation**:
- The human genome consists of about 6.4 billion base pairs. Each base pair has a length of approximately 0.34 nanometers.
- To find the total length of DNA, you can multiply the number of base pairs by the length of each base pair:
\[ \text{Total Length} = \text{Number of Base Pairs} \times \text{Length of Each Base Pair} \]
\[ \text{Total Length} = 6.4 \text{ billion} \times 0.34 \text{ nm} \]
- This calculation confirms that the total length of DNA in a diploid human cell is about 2.2 meters.

5. **Conclusion**:
- Therefore, the 2.2 meter long thread of DNA is distributed among the 46 chromosomes located in the nucleus of a human cell.

### Final Answer:
The 2.2 meter long thread of DNA is distributed in the 46 chromosomes present in the nucleus of a human cell.

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