Microtubules, essentially miniature strings, splay out from opposite ends of the cell and shorten, pulling apart the sister chromatids of each chromosome.[5]
Thus, a cell grows (G1), continues to grow as it duplicates its chromosomes (S), grows more and prepares for mitosis (G2), and finally it divides (M) before restarting the cycle.[4]
[edit] PreprophaseMain article: Preprophase
In plant cells only, prophase is preceded by a pre-prophase stage.
organic process consisting of the division of the cytoplasm of a cell following karyokinesis bringing about the separation into two daughter cells
Cytokinesis has already begun; the pinched area is known as the cleavage furrow.
[edit] Prophase
Micrograph showing condensed chromosomes in blue and the mitotic spindle in green during prometaphase of mitosisMain article: Prophase
Normally, the genetic material in the nucleus is in a loosely bundled coil called chromatin.
one of a pair of small cylindrical cell organelles near the nucleus in animal cells; composed of nine triplet microtubules and form the asters during mitosis
The cells of higher plants (such as the flowering plants) lack centrioles; instead, microtubules form a spindle on the surface of the nucleus and are then being organized into a spindle by the chromosomes themselves, after the nuclear membrane breaks down.[7]
the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins; during mitotic division it condenses into chromosomes
a stick or pin used to twist the yarn when making thread
In addition to phragmosome formation, preprophase is characterized by the formation of a ring of microtubules and actin filaments (called preprophase band) underneath the plasma membrane around the equatorial plane of the future mitotic spindle.