Leading strand is

Options

A. replicated strand of DNA which grows continuously and does not require DNA ligase
B. replicated strand of DNA which is formed in short segments and requires ligase
C. having its 5' end open for elongation
D. 1 and 3

Answer

**Step-by-Step Solution:**

1. **Understanding the Leading Strand:**
- The leading strand is one of the two strands of DNA that is synthesized during DNA replication. It is synthesized continuously in the direction of the replication fork.

2. **Characteristics of the Leading Strand:**
- The leading strand grows continuously without interruption. This means that as the DNA unwinds, nucleotides are added in a continuous manner.

3. **Role of DNA Ligase:**
- DNA ligase is an enzyme that joins together short segments of DNA. However, it is not required for the leading strand because it does not have short segments; it is synthesized as a continuous strand.

4. **Direction of Synthesis:**
- The leading strand is synthesized in the 5' to 3' direction. This means that nucleotides are added to the 3' end of the growing strand.

5. **Identifying the Correct Option:**
- Given the options:
- A) Replicated strand of DNA which grows continuously and doesn't require DNA ligase.
- B) Replicated strand of DNA which is formed in short segments and requires ligase.
- C) Having its 5' end open for elongation.
- The correct option is A, as it accurately describes the leading strand.

6. **Conclusion:**
- The leading strand is the strand of DNA that is replicated continuously during DNA replication and does not require DNA ligase.

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