AP BIOLOGY

Detailed explanation-1: -During G1, the cell is metabolically active and continuously grows but does not replicate its DNA. G1 is followed by S phase (synthesis), during which DNA replication takes place.

Detailed explanation-2: -The S Phase of Interphase The S phase of a cell cycle occurs during interphase, before mitosis or meiosis, and is responsible for the synthesis or replication of DNA.

Detailed explanation-3: -S phase. In S phase, the cell synthesizes a complete copy of the DNA in its nucleus. It also duplicates a microtubule-organizing structure called the centrosome. The centrosomes help separate DNA during M phase.

Detailed explanation-4: -DNA synthesis begins in S phase as the replicative helicase unwinds and separates the two strands of the DNA double helix [7]. As the helicase unwinds DNA, DNA polymerase synthesizes DNA utilizing the exposed single stranded DNA as a template.

Detailed explanation-5: -During the S phase, synthesis of DNA occurs which makes the DNA content become 4C. At the end of meiosis I, the DNA content in the cell again becomes halved, which is 2C. After meiosis II, the DNA content again gets halved and hence final cells produced after meiosis have DNA content as C.