Because histone protien synthesis takes place in s phase while non histone protien synthesis takes place in g2 phase

Explanation:
Histone protein synthesis occurs during S-phase of the cell cycle, which is the phase of DNA replication. Here is a detailed explanation:

S-phase:
- The S-phase of the cell cycle is the period during which DNA synthesis occurs.
- Histone proteins are essential components of chromatin, which is the complex of DNA and proteins that make up chromosomes.
- During the S-phase, new histone proteins are synthesized to package the newly replicated DNA into chromatin structure.

Role of Histone Proteins:
- Histone proteins help in compacting and organizing the DNA into chromatin, which is crucial for proper gene regulation and cell division.
- They also play a role in controlling gene expression and DNA repair processes.

Timing of Histone Protein Synthesis:
- Histone protein synthesis is tightly regulated during the cell cycle to ensure that the newly synthesized DNA is properly packaged.
- The synthesis of histone proteins peaks during the S-phase when DNA replication is occurring.

Conclusion:
Histone protein synthesis is a crucial process that occurs during the S-phase of the cell cycle to facilitate proper packaging of DNA into chromatin structure. This ensures the accurate transmission of genetic information during cell division.