synthesis is the phase of the cell cycle when dna is replicated.
synthesis is the phase of the cell cycle when dna is replicated.
the phase of the cell cycle when dna is replicated?
synthesis
the cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to duplication of its dna (dna replication) and division of cytoplasm and organelles to produce two daughter cells. in bacteria, which lack a cell nucleus, the cell cycle is divided into the b, c, and d periods. the b period extends from the end of cell division to the beginning of dna replication. dna replication occurs during the c period. the d period refers to the stage between the end of dna replication and the splitting of the bacterial cell into two daughter cells. in cells with a nucleus, as in eukaryotes, the cell cycle is also divided into two main stages: interphase and the mitotic (m) phase (including mitosis and cytokinesis). during interphase, the cell grows, accumulating nutrients needed for mitosis, and undergoes dna replication preparing it for cell division. during the mitotic phase, the replicated chromosomes and cytoplasm separate into two new daughter cells. to ensure the proper division of the cell, there are control mechanisms known as cell cycle checkpoints.
cell cycle
the neuronal cell cycle represents the life cycle of the biological cell, its creation, reproduction and eventual death. the process by which cells divide into two daughter cells is called mitosis. once these cells are formed they enter g1, the phase in which many of the proteins needed to replicate dna are made. after g1, the cells enter s phase during which the dna is replicated. after s, the cell will enter g2 where the proteins required for mitosis to occur are synthesized. unlike most cell types however, neurons are generally considered incapable of proliferating once they are differentiated, as they are in the adult nervous system. nevertheless, it remains plausible that neurons may re-enter the cell cycle under certain circumstances. sympathetic and cortical neurons, for example, try to reactivate the cell cycle when subjected to acute insults such as dna damage, oxidative stress, and excitotoxicity. this process is referred to as “abortive cell cycle re-entry” because the cells usually die in the g1/s checkpoint before dna has been replicated.
neuronal cell cycle