Question

answer the following question with two supporting pieces of evidence

explain what happens (structure and function) to the mitotic spindle throughout the stages of mitosis

Answer 1

Ans. -

The mitotic spindle is a structure composed of microtubules which segregates chromosomes into the daughter cells during mitosis. A microtubule is a rope-like component of the cytoskeleton. The centrosome is an organelle that serves as a microtubule organizing center during cell division.

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.

Spindle fibers are highly active during mitosis. Chromosomes are held to the metaphase plate by the force of spindle fibers pushing on their centromeres. Anaphase: Spindle fibers shorten and pull sister chromatids toward spindle poles. Separated sister chromatids move toward opposite cell poles. The mitotic spindle also begins to develop during prophase . As the cell's two centrosomes move toward opposite poles, microtubules gradually assemble between them, forming the network that will later pull the duplicated chromosomes apart.