The replication of DNA in eukaryotes takes place at X = ................... the cell-cycle. The two processes: DNA replication and cell division should be 3' highly coordinated as failure in cell division after DNA replication results Into Y = ....... .

Options

A. X = M-Phase, Y = Aneuploidy
B. X = G-Phase, Y = Polyploidy
C. X = S-Phase, Y = Polyploidy
D. X = F-Phase, Y = Haploidy

Explanation

To solve the question, we need to identify the correct answers for X and Y based on the information provided about DNA replication and the cell cycle in eukaryotes.

### Step-by-Step Solution:

1. **Understanding the Cell Cycle**:
- The cell cycle consists of several phases that a cell goes through to divide and replicate. The two main phases are Interphase and the Mitotic phase (M phase).
- Interphase is further divided into three sub-phases: G1 (Gap 1), S (Synthesis), and G2 (Gap 2).

2. **Identifying X**:
- DNA replication specifically occurs during the S phase of Interphase. During this phase, the cell synthesizes a complete copy of the DNA in its nucleus.
- Therefore, X = S phase.

3. **Understanding Coordination of Processes**:
- The question states that DNA replication and cell division must be highly coordinated. If cell division does not occur after DNA replication, it can lead to problems.

4. **Identifying Y**:
- If DNA replication occurs but cell division does not follow, the cell will have double the amount of genetic material. This condition is known as polyploidy, where the cell has more than two paired (homologous) sets of chromosomes.
- Therefore, Y = polyploid.

5. **Final Answers**:
- X = S phase
- Y = polyploid

### Conclusion:
The replication of DNA in eukaryotes takes place at **X = S phase** of the cell cycle. The failure in cell division after DNA replication results in **Y = polyploid**.

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