What happens during S phase ?

Explanation

### Step-by-Step Text Solution:

1. **Understanding the Cell Cycle**: The cell cycle is a series of phases that a cell goes through as it grows and divides. It includes several stages: G1 (Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitosis).

2. **Identifying the S Phase**: The S phase, or Synthesis phase, is a crucial part of the cell cycle where significant cellular activities occur.

3. **DNA Replication**: During the S phase, the primary event is the replication of DNA. Each chromosome is duplicated to ensure that when the cell divides, each daughter cell receives an identical set of chromosomes.

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