Spindle fibers form a protein structure that divides the genetic material in a cell. The spindle is
necessary to equally divide the chromosomes in a parental cell into two daughter cells during both types of nuclear division: mitosis and meiosis.
At the beginning of nuclear division, two wheel-shaped protein structures called
centrioles position themselves at opposite ends of the cell forming cell poles. Long protein fibers called microtubules extend from the centrioles in all possible directions, forming what is called a spindle.
Some of the microtubules attach the poles to the chromosomes by connecting to protein complexes called kinetochores. Kinetochores are protein formations that develop on each chromosome around
the centromere, which is a region located near the middle of a chromosome.
Other microtubules bind to the chromosome arms or extend to the opposite end of the cell. During the cell division phase called metaphase, the microtubules pull the chromosomes back and forth until they align in a plane along the equator of the cell, which is called the equatorial plane.
The cell goes through an important checkpoint to ensure that all of the chromosomes are attached to the spindle and ready to be divided before it proceeds with division. Next, during anaphase, the chromosomes are simultaneously separated and pulled by the spindle to opposite poles of the cell.
Chromosomes attach to the mitotic spindle during the metaphase of mitosis. Part of the answer depends on how you define the stages of mitosis and not everybody does this the same way. The short answer is all of them.
the spindle fibers
Spindle Fibers
the spindle
Centrioles
During mitosis a double-stranded chromosome attaches to a spindle fiber centromere.
The answer is telophase.
Chromosomes attach to the mitotic spindle during the metaphase of mitosis. Part of the answer depends on how you define the stages of mitosis and not everybody does this the same way. The short answer is all of them.
Separation of chromatids during anaphase .
spindle
the spindle fibers
Spindle Fibers
the spindle
Centrioles
kinetochore microtubules bind with spindle fibers.
The centrioles within the cell form the mitotic spindle.
Spindle fibers are necessary in mitosis as they help in bringing half the number of chromosomes on each side of the cell, so that when the cell divides, the chromosomes are distributed equally in both the daughter nuclei.