Chromosomes are usually visible beneath a mild microscope handiest when the cell is present process the metaphase of mobile department (wherein all chromosomes are aligned inside the center of the cell in their condensed form).[4] Before this takes place, each chromosome is copied as soon as (S section), and the replica is joined to the original by way of a centromere, resulting either in an X-fashioned shape (pictured here) if the centromere is located within the center of the chromosome or a -arm structure if the centromere is located close to one of the ends. The authentic chromosome and the replica are actually referred to as sister chromatids. During metaphase the X-form structure is referred to as a metaphase chromosome. In this rather condensed form chromosomes are easiest to distinguish and have a look at.[5] In animal cells, chromosomes attain their highest compaction stage in anaphase during chromosome segregation.