Difference between g1&g2 phase in cell cycle?

Priya sarda

Cell division is considered as an important aspect of reproduction, growth, and development of an organism. Two types of cell divisions are seen in organisms namely, mitosis and meiosis. The cell cycle is composed of main two phases such as interphase and mitotic phase. Interphase is the longest phase in which cells prepare for division by growing the cell and making a copy of its DNA. Interphase is divided into three substages; G1 phase, S phase, and G2 phase. The duration of these sub-phases depends on the type of organism. G1 phase is the first substage of interphase which has a longer process while the G2 phase is the last substage of interphase and is considered to be relatively a short phase. During the G1 phase, the cell shows first growth by copying organelles and making the molecular building blocks which are necessary for later steps. During the G2 phase, the cell shows the second growth by making proteins and organelles and beginning to reorganize its contents in preparation for mitosis. This is the key difference between G1 and G2 phase of a cell cycle. What is G1 Phase? G1 phase is the first cell growth phase of the interphase of the cell cycle. This is also referred to as Gap 1 stage.  G1 phase is the first substage of interphase. Significant development processes occur within the cell at G1 phase. The cell will increase its size due to the extensive synthesis of proteins and RNA that causes the cell growth. It also helps during the replication of DNA. Proteins that synthesize during G1 phase include mainly histone proteins. The majority of RNA synthesized is mRNA. Histone proteins and mRNA involves during DNA replication. What is G2 Phase? During the interphase of the cell cycle, once the G1 phase and S phase is completed, the cell will enter into the G2 phase. It is also known as the Gap 2 phase. G2 phase is the final substage of interphase. When compared with G1 phase, the G2 phase is a shorter phase.  It is considered to be an important phase in the cell cycle in the context of growth and protein synthesis since extensive cellular growth take place under high synthesis rate of proteins. With the synthesis of necessary RNA and proteins, it also helps the formation of spindle apparatus during mitosis. Even though this phase is considered as important, this stage could be avoided by a cell and thus, can directly enter into the mitosis phase once S phase is completed. But by completing G2 phase, cell become fully prepared for mitosis. G1 Phase vs G2 Phase of Cell Cycle G1 phase is the first phase of the interphase of the cell cycle in which cell shows a growth by synthesizing proteins and other molecules.G2 phase is the third phase of interphase of the cell cycle in which cell prepares for nuclear division by making necessary proteins and other components. Sub Stage of Inter PhaseThe first substage of interphase is a G1 phase.The last substage of interphase is a G2 phase. Synthesis of RNA and ProteinsOccur in G1 phase for cell growth and DNA replicationOccur in G2 phase which is essential for spindle formation and mitosis. ProgressionG1 phase proceeds into S phase where DNA replication occurs.G2 phase proceeds into the mitotic stage.