Summary
Nuclear division that produces two genetically identical daughter nuclei with the same chromosome number as the parent.
In depth
Phases: prophase (condensation, spindle forms), prometaphase (envelope breaks, kinetochores attach), metaphase (alignment), anaphase (chromatids separate) and telophase (nuclei re-form). The spindle is built from microtubules organised by centrosomes.
The result is two daughter nuclei each with the same chromosome number and genetic information as the parent (2n to 2n). It supports growth, tissue repair and asexual reproduction.
Common mistake: homologous chromosomes do not pair in mitosis; that happens only in meiosis I.
Chromosome movement uses two forces: kinetochore microtubules shorten to pull chromatids toward poles (anaphase A), and spindle poles move apart as overlapping microtubules slide (anaphase B). The cohesin that holds sisters together is cleaved by an enzyme called separase, which is released when the inhibitor securin is destroyed.
Cells with mistakes in segregation become aneuploid, with an abnormal chromosome count, which is common in cancer. Plant cells lack centrioles but still build spindles, and fungi often keep their nuclear envelope closed during division.
Remember: mitosis is nuclear division and cytokinesis is cytoplasmic division; they usually occur together but are different processes.
Frequently asked questions
What is Mitosis?
Nuclear division that produces two genetically identical daughter nuclei with the same chromosome number as the parent.
Which area of biology covers Mitosis, and how advanced is it?
Mitosis is one of the 52 topics in Cell Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Cytokinesis, Meiosis, Cell Differentiation.
What should I learn before Mitosis?
Work through the Beginner topics in Cell Biology first, such as Cell Theory, Prokaryotic Cell, Eukaryotic Cell, then return to Mitosis. Intermediate topics assume the Beginner vocabulary.
What topics are related to Mitosis?
The closest topics to Mitosis are Cytokinesis, Meiosis, Cell Differentiation, Cell Wall. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Mitosis?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Mitosis. To practise the whole of Cell Biology, use the Cell Biology quiz.
How is Mitosis different from Cytokinesis?
Mitosis: Nuclear division that produces two genetically identical daughter nuclei with the same chromosome number as the parent. Cytokinesis: Division of the cytoplasm after nuclear division, by a cleavage furrow in animals or a cell plate in plants. Read both side by side and note what each one explains.
What is a common mistake about Mitosis?
Homologous chromosomes do not pair in mitosis; that happens only in meiosis I.
How should I study Mitosis step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Cytokinesis and explain the difference aloud. Finally, take the Cell Biology quiz and come back to this page for any question you miss.