Difference Between G1 Phase and G2 Phase

Division or reproduction is a basic need and function of a cell. Cell division is of two types, mitosis and meiosis. This division also has substeps or stages, one of these steps is the interface in which the G1 phase and the G2 phase are also included. G1 phase is also known as Gap 1 phase. It is the first subphase in cell cycle interphase that is observed in eukaryotic cell division. In this phase, messenger RNA (mRNA) and proteins are synthesized in the cell in preparation for mitosis. The G1 phase is the longest phase of the cell cycle, while the G2 phase or Gap 2 phase is the second subphase or interphase stage in the cell cycle following mitosis. The G2 phase follows the proper completion of the S phase of the cell cycle during which a cell’s DNA replicates.

Comparison chart

What is Phase G1?

G1 phase is also known as Gap 1 phase. It is the first substep in interphase of the cell cycle. It is a long process compared to the G2 phase. In the G1 phase, there is an increase in cell size but the organelle does not increase in number. In this state, the synthesis of RNA and useful proteins (histone) that are required for DNA synthesis and other processes in the cell occurs. G1 phase next leads to S phase. The average time for G1 phase is up to 18 hours, which can vary from cell to cell. Also, the G1 phase has many factors that it depends on. These factors are also called growth factors, such as cell environment, temperature, supply of nutrients, proteins and amino acids, etc. The optimum temperature for proper growth is 37 degrees C (98.6 degrees F).

What is Phase G2?

G2 phase is also known as Gap 2 phase. It is the second substep in interphase of the cell cycle. It is a shorter process compared to the G1 phase. In the G2 phase, there is rapid cell growth and protein synthesis. This phase is not the necessary part of the cell cycle, but it allows the cell to be fully prepared for mitosis. The G2 phase indicates the successive completion of the S phase, in which DNA replication takes place. The size of the cell in which the nucleus also grows increases, almost all cell organelles increase in number. The RNAs and proteins necessary for spindle formation are synthesized in this phase. The G2 phase ends as prophase (the first step in mitosis) and is regulated by the cell itself, since everything depends on the cell’s genetic information.

Phase G1 vs. Phase G2

• G1 phase is also known as Gap 1 phase, and is the first substep in interphase of the cell cycle, while G2 phase is also known as Gap 2 phase and is the second substep in interphase of the cell.
• The G1 phase is a long process while the G2 phase is a shorter process compared to the G1 phase.
• The G1 phase leads to the S phase, while the G2 phase indicates the successive completion of the S phase.
• In G1 phase, there is an increase in cell size but the organelle does not increase in number, on the other hand, in G2 phase the cell size increases in which the nucleus also grows, almost all cell organelles increase in number .
• In the G1 phase, the synthesis of RNA and useful proteins (histones) that are required for DNA synthesis and other processes in the cell occurs here, while in the G2 phase, RNA and proteins are synthesized that are required for spindle formation.