During the cell cycle, the amount of DNA in a cell doubles from its initial value, but there is no increase in the chromosome number. Which phase of the cell cycle is directly responsible for bringing about this change?

Step-by-step solution

During the S phase (Synthesis phase) of the cell cycle, DNA replication takes place. This results in the doubling of the amount of DNA per cell (for example, from 2C to 4C). However, because the newly synthesized sister chromatids remain attached at the centromere, there is no increase in the chromosome number. A cell that had a diploid number of chromosomes (2n) at G₁ will still have 2n chromosomes at the end of the S phase. G₁ and G₂ are growth phases where DNA content does not double, and Anaphase is characteriz