G₂ phase is a the 3rd and final subphase in interphase of the cell cycle. It follows successful completion of DNA synthesis and chromosomal replication in S phase, and occurs during a period of time - often four to five hours. This far into interphase the nucleus is well defined and bound by a nuclear envelope. It contains at least one nucleolus. Although the chromosomes have been replicated they can not yet be distinguished individually because they are still in the form of loosely packed chromatin fibers. The phase prepares the cell for mitosis, or M phase, initiated by prophase. The cell cycle, or cell-division cycle (CDC), is the series of events in a eukaryotic cell between one cell division and the next. ... DNA replication. ... This article or section does not cite its references or sources. ... DNA replication. ... Mitosis divides genetic information during cell division. ... Prophase, with the mitotic spindles stained green and the cell nucleus and chromatin stained blue. ...

At the end of this gap is another control checkpoint, the G₂ Checkpoint, to determine if the cell can now proceed to enter M phase and divide. The G₂ checkpoint prevents cells from entering mitosis when DNA was damaged since the last division, providing an opportunity for DNA repair and stopping the proliferation of damaged cells. Because the G₂ checkpoint helps to maintain genomic stability, it is an important focus in understanding the molecular causes of cancer. Cell cycle checkpoints exist at specific points in the cell cycle in eukaryotic cells to prevent them from progressing to the next phase of the cell cycle in the event of DNA damage or another condition which would make cell division dangerous for the cell. ... This article or section does not cite its references or sources. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... DNA damage resulting in multiple broken chromosomes DNA repair is a process constantly operating in cells; it is essential to survival because it protects the genome from damage and harmful mutations. ... Genomics is the study of an organisms genome and the use of the genes. ... Cancers are caused by a series of mutations. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ...