Which of the following is wrong about S-phase ?

Options

A. DNA duplication occur in S-phase
B. Cell synthesized Histone protein in S-phase
C. Centriole duplication occur in S-phase
D. Synthesis of tubulin in S-phase

Answer

To determine which statement is wrong about the S-phase, we need to analyze the key events that occur during this phase of the cell cycle. The S-phase, or synthesis phase, is primarily characterized by the following processes:

1. **DNA Replication**: The most critical event in the S-phase is the replication of nuclear DNA. This ensures that each daughter cell will receive an identical set of chromosomes.

2. **Histone Synthesis**: Along with DNA replication, histone proteins, which are essential for packaging DNA into chromatin, are synthesized during this phase.

3. **Centriole Duplication**: The centrioles, which play a crucial role in cell division, also duplicate during the S-phase.

4. **Tubulin Synthesis**: Tubulin is a protein that forms microtubules, which are part of the cytoskeleton and are involved in various cellular processes, including mitosis. However, the synthesis of tubulin is not specifically a hallmark of the S-phase.

Now, let's evaluate the options provided:

- **Option 1**: DNA duplication occurs in S-phase. (Correct)
- **Option 2**: Cell synthesizes histone proteins in S-phase. (Correct)
- **Option 3**: Centriole duplication occurs in S-phase. (Correct)
- **Option 4**: Synthesis of tubulin in S-phase. (Wrong)

Based on the analysis, the statement that is wrong about the S-phase is that tubulin synthesis occurs during this phase.

### Final Answer:
The wrong statement about the S-phase is: "Synthesis of tubulin in S-phase."