---

Centromere is a primary constriction present in the chromosome. It provides orientation to chromosome and marks the space for attachment of chromosomal fibres during cell division. The centromere has disc shaped structures called kinetochores on the sides of it.

Depending upon the location of centromere in a chromosome, the chromosome is classified  into the following four types :

(a) Telocentric: Centromere is present at the terminals.

(b) Acrocentric: Centromere is present near the terminals resulting in two short arms and two long arms. 

(c) Sub- metacentric : Centromere divides the chromosomes into two unequal arms. It lies either below centre or above centre.

(d) Metacentric : Centromere divides the chromosomes into two equal arms with the centromere in the middle.