AP BIOLOGY

Detailed explanation-1: -S phase is the period during which DNA replication occurs.

Detailed explanation-2: -The interphase of a normal cell cycle will thus, consist of the G1 (Gap 1) phase, S (Synthesis) phase, and G2 (Gap 2) phase. The S phase is the phase in which replication of DNA will take place which is then followed by histones synthesis. This is the phase taking place between the G1 phase and G2 phase.

Detailed explanation-3: -Initially in G1 phase, the cell grows physically and increases the volume of both protein and organelles. In S phase, the cell copies its DNA to produce two sister chromatids and replicates its nucleosomes. Finally, G2 phase involves further cell growth and organisation of cellular contents.

Detailed explanation-4: -Also known as gap 1 phase, it is the first phase of the cell cycle in cell division. The cell is metabolically active and continuously grows in this phase of the cell cycle. However, no DNA replication takes place in this phase.