Which of the following is correct ?

Options

A. Autoradiographs are "pictures" of a resulting DNA sequencing reactions and are used to inter the nucleotide sequence of a given DNA molecule.
B. A single standed nucleic acid (DNA or RNA) of known sequence or origin used to detect the presence of desired target DNAs is called probe.
C. Technique of insertion of a desired gene in DNA of plasmid vector is called Gene splicing
D. All

Answer

To determine which of the statements is correct, let's analyze each option step by step:

### Step 1: Analyze the First Statement
**Statement**: "Autoradiographs are pictures of resulting DNA sequence reactions and are used to enter the nucleotide sequence of a given DNA molecule."

**Analysis**:
- Autoradiographs are indeed images that show the distribution of radioactive isotopes in a sample. They are commonly used in molecular biology to visualize DNA or RNA fragments after gel electrophoresis.
- They do provide information about the nucleotide sequence, but they do not directly represent the sequence itself. Instead, they show where the labeled nucleotides are located on the gel.

**Conclusion**: This statement is partially correct but could be misleading as it implies a direct representation of the sequence.

### Step 2: Analyze the Second Statement
**Statement**: "Single-stranded nucleic acid DNA or RNA of known sequence or origin used to detect the presence of desired target DNA is called a probe."

**Analysis**:
- This statement accurately defines a probe. Probes are indeed single-stranded nucleic acids that can hybridize with complementary sequences in target DNA or RNA. They are used in various techniques to detect the presence of specific nucleic acid sequences.

**Conclusion**: This statement is correct.

### Step 3: Analyze the Third Statement
**Statement**: "Technique of insertion of a desired gene in DNA plasmid vector is called gene splicing."

**Analysis**:
- Gene splicing typically refers to the process of joining together different segments of DNA, often involving the removal of introns and joining exons. However, the term "gene splicing" is not commonly used to refer to the insertion of a gene into a plasmid vector. The more appropriate term would be "gene cloning" or "gene insertion."
- The description of exons and introns is somewhat accurate, but the overall definition provided is misleading.

**Conclusion**: This statement is incorrect.

### Final Conclusion
Based on the analysis:
- The first statement is misleading.
- The second statement is correct.
- The third statement is incorrect.

Thus, the correct answer is that only the second statement is correct.

### Final Answer
The correct option is: **Only the second statement is correct.**

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