AP BIOLOGY

Detailed explanation-1: -In the eukaryotic cell cycle, chromosome duplication occurs during “S phase” (the phase of DNA synthesis) and chromosome segregation occurs during “M phase” (the mitosis phase).

Detailed explanation-2: -All proteins including enzymes required for DNA replication are synthesized in G1 phase while DNA replication occurs in S phase. In G2 phase proteins needed for cell division are synthesized and in M phase cell division occurs.

Detailed explanation-3: -S phase is the period during which DNA replication occurs.

Detailed explanation-4: -Cell cycle is the name we give the process through which cells replicate and make two new cells. Cell cycle has different stages called G1, S, G2, and M. G1 is the stage where the cell is preparing to divide. To do this, it then moves into the S phase where the cell copies all the DNA. So, S stands for DNA synthesis.