The spindle fibre is attached to which of the following specific regions of the chromosomes?

Spindle fibres, which are composed of microtubules, attach to chromosomes at a specialized proteinaceous structure called the kinetochore [1]. The kinetochore is located on the surface of the centromeric heterochromatin. During mitosis, the centromere serves as the foundation for the assembly of the kinetochore; without a centromere, the kinetochore will not assemble, and the chromosome will fail to segregate properly. The interaction between spindle microtubules and kinetochores is essential for bi-orientation, where sister kinetochores attach to microtubules from opposite spindle poles to ensure faithful chromosome segregation into daughter cells [1]. While centrioles help organize the spindle apparatus and telomeres protect the ends of chromosomes, it is specifically the kinetochore that serves as the physical attachment site for the spindle fibres during cell division.

Sources

1. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC4568440/