The discontinuously synthesised fragment are joinied by the enzyme_______ during DNA replication.

Answer

**Step-by-Step Solution:**

1. **Understanding DNA Replication**: DNA replication is the process by which a cell makes an identical copy of its DNA. This involves unwinding the double helix and synthesizing new strands complementary to the original strands.

2. **Identifying the Fragments**: During DNA replication, the leading strand is synthesized continuously, while the lagging strand is synthesized in short segments known as Okazaki fragments. These fragments are formed because DNA can only be synthesized in the 5' to 3' direction.

3. **Role of Okazaki Fragments**: Okazaki fragments are short sequences of DNA nucleotides that are synthesized discontinuously on the lagging strand. In eukaryotes, these fragments are typically 150 to 200 base pairs long.

4. **Joining the Fragments**: After the Okazaki fragments are synthesized, they need to be joined together to form a continuous DNA strand. This is where a specific enzyme comes into play.

5. **Identifying the Enzyme**: The enzyme responsible for joining the Okazaki fragments is called DNA ligase. DNA ligase catalyzes the formation of phosphodiester bonds between the fragments, effectively linking them together.

6. **Final Answer**: Therefore, the enzyme that joins the discontinuously synthesized fragments during DNA replication is **DNA ligase**.

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