ProphaseThe first stage, when chromosomes condense and become visible. The nuclear envelope starts to break up, and the centrosomes begin moving apart.
PrometaphaseThe envelope breaks into pieces. Kinetochores form at the centromeres, and spindle fibers from both poles attach to them.
MetaphaseThe chromosomes line up on the metaphase plate, halfway between the poles. They are at their most condensed.
AnaphaseThe sister chromatids separate and are pulled to opposite poles. Each is now a chromosome, and the cell lengthens.
Telophase and cytokinesisChromosomes reach the poles and loosen. New nuclear envelopes form, and cytokinesis divides the cell in two.
CentrosomeFound at each pole of the cell. The spindle microtubules grow from it.
Spindle fibersMicrotubules of the mitotic spindle. They attach at the kinetochores and pull the chromatids apart.
Cleavage furrowIn animal cells, a ring of actin pulls the membrane inward. This happens at the old metaphase plate, until the cell splits in two.
Inside the cells: 8 5
ChromosomesCopied chromosomes coiling tightly in prophase. So they now show under a light microscope.
Nuclear envelopeThe membrane round the nucleus. It breaks up in prophase and forms again round each new set of chromosomes in telophase.
Metaphase plateThe plane halfway between the poles where the chromosomes line up.
Sister chromatidsThe two identical copies of a chromosome. They are held together until anaphase, when they separate at the centromere.
KinetochoreA protein structure at the centromere of each chromatid. It binds the spindle microtubules.
How this list was compiled: Read 2026-09-26. OpenStax Biology 2e, section 10.2 The Cell Cycle, https://openstax.org/books/biology-2e/pages/10-2-the-cell-cycle : prophase (nuclear envelope dissociating, nucleolus dispersing, centrosomes moving to opposite poles, spindle microtubules extending, sister chromatids coiling and becoming visible); prometaphase (envelope fragmenting further, a kinetochore forming at each sister chromatid's centromeric region and binding spindle microtubules from opposite poles); metaphase (chromosomes aligned on the metaphase plate or equatorial plane, maximally condensed, sisters held by cohesin); anaphase (cohesin degrading, sister chromatids separating at the centromere and pulled toward the centrosomes, each now a chromosome, the cell elongating); telophase (chromosomes reaching the poles and decondensing, spindles depolymerising, nuclear envelopes forming); cytokinesis in animal cells by a contractile ring of actin forming the cleavage furrow at the former metaphase plate. Licence: own work
The drawing: Drawn for this site by script, 2026-09-26. Own work, nothing traced. Licence: own work
How it works
A mitosis labeled diagram of an animal cell: five cells in a row, one for each stage, with the parts that do the work picked out inside them. Start with the 8 main parts, then label the stages of mitosis in order.
Read the full guide
The stages in order
Prophase condenses the chromosomes and breaks up the envelope; prometaphase hooks them to the spindle; metaphase lines them up on the plate; anaphase pulls the sister chromatids apart; telophase rebuilds two nuclei while cytokinesis splits the cell.
What pulls the chromosomes
Spindle fibres grow from the centrosomes at the two poles and grip each chromatid at its kinetochore. In anaphase they pull each chromatid, now a chromosome in its own right, to its pole.
Metaphase is Middle, Anaphase is Apart: the chromosomes line up in the middle, then move apart.
Questions and answers
What happens in anaphase?
The proteins holding the sister chromatids together break down, the chromatids separate at the centromere, and spindle fibres pull each one toward a pole. The cell grows longer as they go.
Is cytokinesis part of mitosis?
Strictly, mitosis divides the nucleus and cytokinesis divides the cytoplasm, usually just after. In animal cells a ring of actin pinches the cell in two at the cleavage furrow.
What is the metaphase plate?
The plane halfway between the two poles of the cell, where the chromosomes line up during metaphase.