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. During mitosis, the spindle fibers are called the mitotic spindle.
What is meant by mitotic spindle?
Definition. The mitotic spindle is the microtubule-based bipolar structure that segregates the chromosomes in mitosis. The poles of the mitotic spindle are made up of centrosomes and the chromosomes are lined up at the spindle equator to ensure their correct bi-orientation and segregation.
What is the mitotic spindle What is its function?
A Survey of Cell Biology
The mitotic spindle is the macromolecular machine that segregates chromosomes to two daughter cells during mitosis. The major structural elements of the spindle are microtubule polymers, whose intrinsic polarity and dynamic properties are critical for bipolar spindle organization and function.
What is another word for mitotic spindle?
In anaphase, the spindle fibers pull the chromatids apart toward opposite poles. Synonym(s): mitotic apparatus. nuclear spindle.
What organizes mitotic spindle?
Alignment of the chromosomes is an important step in mitosis, and it’s accomplished by microtubules, which are rope-like components of the cytoskeleton. Now, microtubules organize into what is known as the mitotic spindle. … Microtubules are the major component of the mitotic spindle.
What type of proteins make up the mitotic spindle?
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.
What are the components of the mitotic spindle?
The mitotic spindle is a special device essential for chromosome segregation ( mitosis) during cell division. It consists of three parts, chromosomes, two asters and a spindle region (Fig. 1). The overall shape of the mitotic spindle is due to microtubules, which are made of α and β-tubulin subunits.
Is responsible for mitotic spindle and microtubule formation?
As the sole microtubule-organizing center (MTOC) in these cells that have a closed mitosis (the nuclear envelope stays intact throughout the cell cycle), the SPB must have access to the nucleoplasm to form the microtubules of the mitotic spindle and to the cytoplasm to form the astral microtubules that will position …
What is the difference between spindle and microtubules?
They are the same thing. As the others have written, microtubules are a “track” that can move organelles around when “motor” proteins (that cleave ATP) pull those organelles. The spindle is what moves the chromosomes during mitosis and meiosis.