Q.Describe the structure of chromosome with a suitable diagram.

A metaphase chromosome has two sister chromatids joined at a centromere (bearing kinetochores), which divides each chromatid into two arms; chromatin coiling makes up each chromatid, and telomeres cap and protect the...

Chromosome = 2 chromatids joined at the centromere, with kinetochores, arms, and telomere-capped ends.

A typical metaphase chromosome is made up of two identical sister chromatids, each formed by the tight coiling and condensation of a single continuous chromatin fibre (DNA wound around histone proteins). The two chromatids remain joined together at a constricted region called the centromere (the primary constriction), which is essential for chromosome movement, since it bears a disc-shaped protein structure called the kinetochore on either side, to which spindle fibres attach during cell division. The position of the centromere divides each chromatid into two arms of characteristic length (a shorter arm and a longer arm), and this position also determines the chromosome's shape category (metacentric, sub-metacentric, acrocentric or telocentric). Some chromosomes additionally show a secondary constriction, associated with the organisation of the nucleolus (hence called the nucleolar organiser region), and such chromosomes are te …