is that part of the cell cycle when thecell is doing its 'normal job. Typically Interphase is viewed as having threebig phases. During the S phase, new is synthesized by the cell resulting in each chromosome with two molecules ofDNA. These are attached together at a structure called the centromere. Eachchromosome is called a duplicated or replicated chromosome because it consistsof two identical DNA molecules. Remember that interphase is not part ofmitosis!
DNA replication occurs in the synthesis or S phase of the Cell Cycle. Every is copied with high fidelity in a process that involves a large number of enzymes. In this process, the double-stranded DNA is unwound and each individual strand is used as a template for the production of the complementary strand. The end result is the production of two identical copies of the genetic material. This process is depicted in the animation below.
Prophase, the first step in mitosis involves the chromosomes becomingvisible, and the nuclear membrane disintegrating. In animals and other organismsthat have them, paired (centrosomes)move to opposite ends of the cell. If you look at a stained cell duringprophase typically you will see what looks like a mass of spaghetti. Duringvery early prophase a big tip that the cell is no longer in interphase is thatthe nucleoli have disappeared and the nuclear material appears grainy.
(French : S phase) Interphase which usually lasts much longer than mitosis is itself divided into stages. Of the interphasic stages, Gap 1 (G1) which lies between the end of telophase and the beginning of the Synthesis (S) periods is the longest; DNA synthesis takes place during the S period.