Different types of chromosomes on the basis of the position of centromere
Centromere: In each chromosome, in colored form of metaphase of mitosis and metaphase-2 of meiosis a colorless pan is seen called centromere. It is also called the primary constriction.
Classification of chromosomes according to the position of centromere:
The structure of chromosome in anaphase stage depends upon centromere.
The type of chromosome on the basis of the position of centromere is stated below:
(i) Metacentric: When centromere is present at the middle of the chromosome then the chromosome is called metacenric chromosome. It looks like the English letter “V”.
(ii) Sub-metacentrie: When the centromere is present slightly away from the middle. It is called the sub-metacentric chromosome, which looks like the English letter ‘L’.
(iii) Acrocentric: It is said to be an acrocentric chromosome, when centromere is present towards the end of the chromosome. It looks like the English letter ‘J’.
(iv) Telocentric: Here the centromere is strictly confined to the end of the chromosome. It looks like the English letter “I”.
(v) Acentric: Centromere is absent in this type or chromosome.