The Stages of Mitosis

Prophase
 1st stage of mitosis
 Chromatin form into chromosomes
 The nuclear envelope begins to break down
 The 2 pair of centrioles begin to move to opposite ends of the cell
 Spindle fibers and asters begin to appear – made of microtubules

Metaphase
 2nd stage of mitosis
 Chromosomes begin to line up at the middle (the equator) of the cell on
specialized spindle fibers called kinetochore fibers

Anaphase
 3rd phase of mitosis
 The chromatids divide at the centromeres and move to opposite sides (poles) of
the cell with the aid of specialized spindle fibers called polar fibers and
kinetochore fibers

Telophase
 The final phase of mitosis
 Centrioles and spindle fibers disappear
 Chromosomes become chromatin again
 Nuclear envelopes begin to form around the new developing daughter cells

Cytokinesis
 Immediately follows mitosis (sometimes included in telophase)
 Occurs when the cytoplasm from the parent cell divides equally between the 2
new daughter cells
o All organelles and structures are also divided equally during this process
o Cell membrane pinches in and divides the cell at its center – called a
cleavage furrow
o Cell membrane eventually divides in two, forming 2 complete daughter
cells – each with its own cell membrane