Final answer:
During interphase, the cell undergoes three distinct periods: G1, S, and G2. G1 is the first phase where the cell accumulates DNA building blocks and energy reserves. S phase is when DNA replication occurs, and G2 is the phase where the cell prepares for cell division.
Step-by-step explanation:
The three stages of interphase, G1, S, and G2, are part of the cell cycle and occur before cell division. During G1, the cell is actively accumulating the building blocks of chromosomal DNA and proteins as well as energy reserves. The S phase is when DNA replication occurs and the cell duplicates its genetic material. Finally, during G2, the cell prepares for cell division by making additional proteins and organelles.