Centromeres
A centromere is the portion of DNA where two sister chromatids are joined. The centromeres are vital for cell division. They act to keep sister chromatids aligned, and enable the chromosomes to be lined up in metaphase.
The position of the centromere divides the chromosome into two arms, the long (q), and the short (p).
Chromosomes are classified as metacentric and submetacentric. Metacentric chromosomes have arms of roughly equal length. In some cases metacentric chromosomes are formed by Robertsonian translocations. If arm lengths are unequal the chromosome is referred to as submetecentric. Chromosomes with very small p arms are called acrocentric.
Acrocentric chromosomes can be involved in Robertsonian translocations
The position of the centromere divides the chromosome into two arms, the long (q), and the short (p).
Chromosomes are classified as metacentric and submetacentric. Metacentric chromosomes have arms of roughly equal length. In some cases metacentric chromosomes are formed by Robertsonian translocations. If arm lengths are unequal the chromosome is referred to as submetecentric. Chromosomes with very small p arms are called acrocentric.
Acrocentric chromosomes can be involved in Robertsonian translocations