G1 Phase vs. G2 Phase

Key Differences

Comparison Chart
.
Time Taken
Leads To
Organelles

Main Function

What is G1 Phase?
G1 phase is also known as Gap 1 phase. It is the first sub-step in interphase of the cell cycle. It is a long process as compared to G2 phase. In G1 phase, there is an increase in the size of the cell but the organelle does not increase in number. Synthesis of useful RNAs and proteins (histone) that are required for the synthesis of DNA and another process in the cell occur in this state. G1 phase next leaders to the S phase. The average time for the G1 phase is up to 18 hours that may vary from cell to cell. Moreover, G1 phase has many factors upon which it depends. These factors are also called growth factors such as the environment of cell, temperature, supply of nutrients, proteins and amino acids, etc. The optimum temperature for proper growth is 98.6 degrees F (37 degrees C). Regulation of G1 phase is controlled by cell cycle control system that regulates the timing and increases the coordination.
What is G2 Phase?
G2 phase is also known as Gap 2 phase. It is the second sub-step in interphase of the cell cycle. It is a shorter process as compared to G1 phase. In 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. G2 phase indicates the successive completion of S phase, in which DNA replication takes place. Cell size increases in which nucleus also grow, almost all the cell organelles increases in number. RNAs and proteins that are required for spindle formation are synthesized in this phase. G2 phase ends as prophase (the first step in mitosis), and it is regulated by the cell itself as it all depend upon genetic information of the cell.