Which of the following statement is incorrect for DNA?

Options

A. DNA is a long polymer of deoxyribonucleotide monophosphat.
B. A bacteriophage known as `phi x` 174 has 5386 base pairs
C. Haploid content of human DNA is `3.3x10^(9)bp`
D. 5-methyl- uracil is the nitrogen base found in DNA

Answer

To determine which statement is incorrect regarding DNA, let's analyze each statement provided:

1. **Statement A**: "DNA is a long polymer of deoxyribonucleotide."
- **Analysis**: This statement is correct. DNA is indeed a polymer made up of repeating units called deoxyribonucleotides. Each deoxyribonucleotide consists of a nitrogenous base, a deoxyribose sugar, and a phosphate group.

2. **Statement B**: "A bacteriophage known as Lambda X174 has 5386 base pairs."
- **Analysis**: This statement is incorrect. The bacteriophage Lambda X174 is composed of single-stranded DNA, which means it contains nucleotides, not base pairs. The correct information is that it has 5386 nucleotides, not base pairs.

3. **Statement C**: "The haploid content of human DNA is 3.3 into 10 to the power 9 base pairs."
- **Analysis**: This statement is correct. The haploid human genome contains approximately 3.3 billion base pairs.

4. **Statement D**: "5-methyl uracil is the nitrogenous base found in DNA."
- **Analysis**: This statement is correct. 5-methyl uracil refers to thymine, which is indeed a nitrogenous base found in DNA.

**Conclusion**: The incorrect statement regarding DNA is **Statement B**.

### Step-by-Step Solution:
1. Identify the statements related to DNA.
2. Analyze each statement for accuracy.
3. Confirm that Statement A is correct.
4. Identify Statement B as incorrect due to the misrepresentation of base pairs in single-stranded DNA.
5. Confirm that Statement C is correct regarding the haploid content of human DNA.
6. Confirm that Statement D is correct regarding thymine being referred to as 5-methyl uracil.
7. Conclude that the incorrect statement is Statement B.