question_answer

The common point of attachment of all the arms of polytene chromosome is known as

A)                  cencromere                     

B)  chromomere

C)                  chromocentre                 

D)  centrosome

Correct Answer: C

Solution :

                 The polytene chromosome was described by Kollar (1882) and first reported by Balbiani (1881) in the salivary gland cells of Chironomus larva. They are found in salivary glands of insects (Drosophild) and are called salivary gland chromosomes. The chromosome is formed by somatic pairs between homologous chromosomes and reported replication or endomitosis of chromonemata. These are attached to chromocentre.                 Chromomeres are bead-like accumulations of chromatin material that are some time visible along interphase chromosomes. These are region of tightly folded DNA.