What are correctly matched :
1. Ligase - Joins short segments of DNA together
2. DNA polymerase - cuts DNA at specific site
3. Helicase - breaks hydrogen bond between complementary pairs during DNA replication

Options

A. 1,2,3 correct
B. 1,2 correct
C. 2,3 correct
D. 1, 3 correct

Answer

To determine which statements are correctly matched, let's analyze each one step by step:

1. **Ligase - Joins short segments of DNA together**:
- This statement is correct. DNA ligase is an enzyme that facilitates the joining of DNA strands by forming a bond between the phosphate group of one strand and the deoxyribose sugar of another. This is essential during DNA replication and repair processes.

2. **DNA polymerase - Cuts DNA at specific site**:
- This statement is incorrect. DNA polymerase is not responsible for cutting DNA. Instead, its primary function is to synthesize new DNA strands by adding nucleotides to a growing DNA chain during DNA replication. The enzyme that cuts DNA at specific sites is called a restriction enzyme or restriction endonuclease.

3. **Helicase - Breaks hydrogen bond between complementary pairs during DNA replication**:
- This statement is correct. Helicase is an enzyme that unwinds the DNA double helix by breaking the hydrogen bonds between the complementary base pairs. This unwinding is crucial for DNA replication as it allows the DNA polymerase to access the single strands of DNA for replication.

Based on the analysis:
- Statement 1 is correct.
- Statement 2 is incorrect.
- Statement 3 is correct.

Thus, the correctly matched statements are 1 and 3.

**Final Answer**: The correct option is "1 and 3 correct".