Select the incorrect statement regarding DNA replication.

Options

A. Leading strand is formed in `5'to3'` direction
B. Okazaki fragments are formed in `5'to3'` direction
C. DNA polymerase catalyses polymerisation in `5' to 3'` direction
D. DNA polymerase catalyses polymerisation in `3' to 5'` direction

Explanation

To solve the question of selecting the incorrect statement regarding DNA replication, we can follow these steps:

### Step-by-Step Solution:

1. **Understand DNA Replication**:
- DNA replication is the process by which a parent DNA molecule is copied to produce two identical daughter DNA molecules.

2. **Identify Key Enzymes**:
- The enzyme responsible for synthesizing new DNA strands is DNA polymerase.

3. **Direction of DNA Synthesis**:
- DNA synthesis occurs in the 5' to 3' direction. This means that nucleotides are added to the growing strand at the 3' end.

4. **Leading and Lagging Strands**:
- During replication, one strand is synthesized continuously in the same direction as the unwinding DNA (leading strand), while the other strand is synthesized in short segments (lagging strand) in the opposite direction.

5. **Okazaki Fragments**:
- The short segments of DNA formed on the lagging strand are called Okazaki fragments, which are synthesized in the 5' to 3' direction.

6. **Review the Statements**:
- Analyze the statements provided in the question:
- Statement 1: Leading strand is formed in 5' to 3' - **True**.
- Statement 2: Okazaki fragments are formed in 5' to 3' - **True**.
- Statement 3: DNA polymerase catalyzes polymerization in 5' to 3' - **True**.
- Statement 4: DNA polymerase catalyzes polymerization in 3' to 5' - **False**.

7. **Select the Incorrect Statement**:
- The incorrect statement is option 4: "DNA polymerase catalyzes polymerization in 3' to 5'".

### Final Answer:
The incorrect statement regarding DNA replication is option 4: "DNA polymerase catalyzes polymerization in 3' to 5'".

---