Final answer:
Cell growth does not only occur in G1 and G2 phases; it also happens during the S phase where DNA replication takes place, effectively doubling the DNA content in preparation for cell division.
Step-by-step explanation:
The statement that cell growth occurs only in the gap phases, G1 and G2, of the cell cycle is false. While significant growth and preparation for cell division do occur during G1 and G2 phases, these are not the only phases where growth happens. During the G1 phase, a cell undergoes major growth, performs its routine functions, and prepares the necessary components for DNA replication.
Subsequently, the S (synthesis) phase follows, where the cell replicates its DNA, effectively doubling its content, which is also associated with certain growth activities. Then, the cell enters the G2 phase, where further growth occurs to prepare for the mitotic (M) phase. During G2, the cell synthesizes proteins and organelles, especially those required for mitosis and cell division, such as microtubules for the mitotic spindle.