AP BIOLOGY

Detailed explanation-1: -Interphase can be divided into three stages: The first growth phase (G1): During the G1 stage, the cell doubles in size and doubles the number of organelles. The synthesis phase (S): The DNA is replicated during this phase.

Detailed explanation-2: -Then, at a critical point during interphase (called the S phase), the cell duplicates its chromosomes and ensures its systems are ready for cell division. If all conditions are ideal, the cell is now ready to move into the first phase of mitosis.

Detailed explanation-3: -G1 or first growth is followed by S phase or synthesis phase. DNA replication occurs in S phase and DNA amount doubles up, i.e., a cell with 2C DNA in G1 phase will now have 4C DNA.

Detailed explanation-4: -The cells in the G2 phase have double the DNA content because the replicated DNA is synthesized and the cell contains double the genetic material. This is necessary before the mitotic division starts resulting in the formation of new cells.