NEET BIOLOGY

Detailed explanation-1: -Spindle fibres constitute mitotic and meiotic spindle during cell division. They are formed by microtubules and play an important role during nuclear division. They are responsible for the segregation of sister chromatids and movement of chromosomes during mitotic and meiotic division.

Detailed explanation-2: -The spindle is a complex microtubule-based superstructure responsible for chromosome movement and segregation during mitosis and meiosis (McIntosh and Koonce 1989; Mitchison 1989a; Rieder 1991; Hyman and Karsenti 1996; Compton 2000).

Detailed explanation-3: -The centromere is the part of a chromosome that links sister chromatids. During mitosis, spindle fibers attach to the centromere via the kinetochore.

Detailed explanation-4: -The kinetochore microtubules from opposite spindle poles pull in opposite directions on each duplicated chromosome, creating, together with a polar ejection force, a tension that helps bring the chromosomes to the spindle equator to form the metaphase plate.

Detailed explanation-5: -The movement of chromosomes is facilitated by a structure called the mitotic spindle, which consists of microtubules and associated proteins. Spindles extend from centrioles on each of the two sides (or poles) of the cell, attach to the chromosomes and align them, and pull the sister chromatids apart.