During the G1 phase of the cell cycle, which processes occur?

• A. Growth and RNA/protein synthesis with no DNA replication
• B. DNA replication
• C. Chromosome condensation
• D. Cytokinesis

Answer: (A)

In the G1 phase, the cell is growing and preparing for DNA replication. Metabolic activities run at a high level, RNA and protein synthesis occur to build the components the cell will need, and the cell increases in size. However, DNA replication has not yet begun, which happens later in the S phase. The other processes are tied to different parts of the cell cycle: DNA replication happens in S phase, chromosome condensation occurs during mitosis (prophase), and cytokinesis occurs after mitosis as the cytoplasm divides. So, growth and RNA/protein synthesis with no DNA replication best describes what happens in G1.