MICROANATOMY

Detailed explanation-1: -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-2: -Powering chromosome movement (microtubules) The most prominent structure in a mitotic cell is the bipolar spindle (made up of microtubules and associated motor proteins), which provides the force to move chromosomes and thereby bring about their segregation.

Detailed explanation-3: -As mitosis progresses, the microtubules attach to the chromosomes, which have already duplicated their DNA and aligned across the center of the cell. The spindle tubules then shorten and move toward the poles of the cell. As they move, they pull the one copy of each chromosome with them to opposite poles of the cell.

Detailed explanation-4: -During metaphase of meiosis I and II, microtubules form a pointed and elongated bipolar spindle, which then shortens during anaphase. In addition, the microtubule density shifts from the spindle poles to the midzone between the separating chromosomes.