The S phase (or synthesis phase) is a period of the cell cycle during which DNA is replicated (or synthesized). G1 and G2 are both growth phases, during which cellular organelles are replicated and the cell grows in size. The M phase refers to mitosis, or cell division.

During the S phase, the cell dedicates its time to replicating its DNA. The S phase is named for the synthesis of DNA.

The G phases are needed for increasing proteins and cellular organelles, and are known for cellular growth. The M phase is also known as mitosis.

There are two stages in the cell cycle marked by the replication of organelles and protein synthesis: G1 and G2. G1 follows mitosis and allows the cell to grow. G2 occurs just before mitosis, and ensures that both daughter cells will have adequate organelles. It also allows proteins necessary for mitosis to be translated.

The overall order of the cell cycle is: G1, S, G2, M. G1 is a growth period. S marks the replication of DNA, resulting in the production of identical sister chromatids. G2 is responsible for organelle synthesis. The M phase is mitosis, or cell division.

The cell cycle consists of four major phases: G1, S, G2, and M.

The G1 phase stands for gap 1 and is when organelles replicate and the cell grows.

The S phase stands for synthesis and is when DNA is replicated.

The G2 phase stands for gap 2 and is when DNA is proofread and DNA damage is repaired.

The M phase is mitosis, which is further broken down into prophase, metaphase, anaphase, telophase, and cytokinesis. Prophase is when the chromosomes condense. Metaphase is when the chromosomes line up at the metaphase plate in the center of the cell. Anaphase is when the sister chromatids are pulled to opposite sides of the cell. Telophase is when the cell begins to split and the nuclear membrane reassembles. Cytokinesis is when the cytoplasm pinches off and two daughter cells are formed. 

G0 is a separate phase, in which the cell cycle is stopped. Cells in the G0 phase are known as quiescent cells, and do not divide.

The cell cycle consists of four major phases: G1, S, G2, and M.

The G1 phase stands for gap 1 and is when organelles replicate and the cell grows.

The S phase stands for synthesis and is when DNA is replicated.

The G2 phase stands for gap 2 and is when DNA is proofread and DNA damage is repaired.

The M phase is mitosis, which is further broken down into prophase, metaphase, anaphase, telophase, and cytokinesis. Prophase is when the chromosomes condense. Metaphase is when the chromosomes line up at the metaphase plate in the center of the cell. Anaphase is when the sister chromatids are pulled to opposite sides of the cell. Telophase is when the cell begins to split and the nuclear membrane reassembles. Cytokinesis is when the cytoplasm pinches off and two daughter cells are formed. 

G0 is a separate phase, in which the cell cycle is stopped. Cells in the G0 phase are known as quiescent cells, and do not divide.

The cell cycle consists of four major phases: G1, S, G2, and M.

The G1 phase stands for gap 1 and is when organelles replicate and the cell grows.

The S phase stands for synthesis and is when DNA is replicated.

The G2 phase stands for gap 2 and is when DNA is proofread and DNA damage is repaired.

The M phase is mitosis, which is further broken down into prophase, metaphase, anaphase, telophase, and cytokinesis. Prophase is when the chromosomes condense. Metaphase is when the chromosomes line up at the metaphase plate in the center of the cell. Anaphase is when the sister chromatids are pulled to opposite sides of the cell. Telophase is when the cell begins to split and the nuclear membrane reassembles. Cytokinesis is when the cytoplasm pinches off and two daughter cells are formed. 

G0 is a separate phase, in which the cell cycle is stopped. Cells in the G0 phase are known as quiescent cells, and do not divide.

The cell cycle consists of four major phases: G1, S, G2, and M.

The G1 phase stands for gap 1 and is when organelles replicate and the cell grows.

The S phase stands for synthesis and is when DNA is replicated.

The G2 phase stands for gap 2 and is when DNA is proofread and DNA damage is repaired.

The M phase is mitosis, which is further broken down into prophase, metaphase, anaphase, telophase, and cytokinesis. Prophase is when the chromosomes condense. Metaphase is when the chromosomes line up at the metaphase plate in the center of the cell. Anaphase is when the sister chromatids are pulled to opposite sides of the cell. Telophase is when the cell begins to split and the nuclear membrane reassembles. Cytokinesis is when the cytoplasm pinches off and two daughter cells are formed. 

G0 is a separate phase, in which the cell cycle is stopped. Cells in the G0 phase are known as quiescent cells, and do not divide.

The cell cycle consists of four major phases: G1, S, G2, and M.

The M phase is mitosis, which is further broken down into prophase, metaphase, anaphase, telophase, and cytokinesis.

Prophase is when the nuclear envelope dissolves and chromosomes condense. Metaphase is when the chromosomes line up at the metaphase plate in the center of the cell. Anaphase is when the sister chromatids are pulled to opposite sides of the cell by spindle fibers. Telophase is when the cell begins to split and the nuclear membrane reassembles. Cytokinesis is when the cytoplasm pinches off and two daughter cells are formed.

The S phase of the cell cycle is the period during which DNA is replicated.

The cell cycle consists of four major phases: G1, S, G2, and M.

The M phase is mitosis, which is further broken down into prophase, metaphase, anaphase, telophase, and cytokinesis.

Prophase is when the nuclear envelope dissolves and chromosomes condense. Metaphase is when the chromosomes line up at the metaphase plate in the center of the cell. Anaphase is when the sister chromatids are pulled to opposite sides of the cell by spindle fibers. Telophase is when the cell begins to split and the nuclear membrane reassembles. Cytokinesis is when the cytoplasm pinches off and two daughter cells are formed.

It is important to note that the cell generates two daughter nuclei during telophase, but the cytoplasm does not divide until cytokinesis. As such, there is a short period during which the cell has two, identical, fully formed nuclei.

The S phase of the cell cycle is the period during which DNA is replicated.

The G0 phase, sometimes called the resting or quiescent phase, is a phase of the cell cycle during which the cell remains in an inactive or dormant state. The G0 phase is often seen as an extension of the first growth phase (G1), during which the cell is not undergoing division or getting ready to undergo division, or it may be seen as a phase that happens separate from the cell cycle completely. Certain types of cells, such as nerve cells, enter into the G0 phase once they are mature, even though they continue to perform their designated functions. Cells enter this inactive stage from a checkpoint present in the G1 phase. Entrance into the G0 phase typically occurs in response to a deficiency of key nutrients and growth factors. The cell will remain in the this stage until these growth factors and nutrients are sufficient enough for the cell to continue through the cell cycle. The G0 phase is not always a component of the normal cell cycle.