Which is synthesized in `G_(1)` phase

Options

A. DNA polymerase
B. Histones
C. Nucleolar DNA
D. Tubulin proteins

Answer

**Step-by-Step Solution:**

1. **Understanding the Cell Cycle Phases:**
- The cell cycle consists of several phases: G1 (Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitosis).
- Each phase has specific activities that occur, contributing to cell growth and division.

2. **Focus on the G1 Phase:**
- The G1 phase is primarily a period of cell growth and preparation for DNA synthesis.
- During this phase, the cell synthesizes various proteins and organelles to support future cell division.

3. **Identifying Key Synthesized Components in G1:**
- In the G1 phase, proteins required for DNA replication are synthesized.
- This includes enzymes such as DNA polymerase, which is essential for DNA synthesis in the subsequent S phase.

4. **Evaluating the Options:**
- **DNA Polymerase:** This enzyme is necessary for DNA replication and must be synthesized during G1 to be available for the S phase.
- **Histones:** These proteins are synthesized during the S phase along with DNA, making this option incorrect for G1.
- **Nuclear DNA:** The synthesis of nuclear DNA occurs in the S phase, so this option is also incorrect for G1.
- **Tubulin Protein:** This protein is crucial for the formation of the mitotic spindle and is synthesized in the G2 phase, making this option incorrect as well.

5. **Conclusion:**
- The only correct answer for what is synthesized in the G1 phase is **DNA polymerase**.

**Final Answer:** DNA polymerase is synthesized in the G1 phase.

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