Glossary
mitosis
Mitosis is the division that grows and repairs a body: one cell becomes two, and each daughter cell carries the same set of chromosomes as the parent.
Mitosis is the division that grows a body and repairs it: one cell becomes two, and each daughter cell carries the same set of chromosomes as the parent cell. It runs in four phases. In prophase the chromosomes condense and the nuclear envelope breaks down. In metaphase they line up along the cell's equator, attached to spindle fibers. In anaphase the sister chromatids separate and move to opposite poles. In telophase two nuclei re-form, and cytokinesis divides the cytoplasm. The point of the sequence is fidelity. Each chromosome is copied before division begins and the copies are pulled apart, so each daughter cell receives one of each. Mitosis is not meiosis: meiosis halves the chromosome number and produces four genetically different cells for reproduction. A question that asks what a daughter cell receives is asking about the copy, not about how many divisions happen — the count matters in meiosis, where two divisions follow one replication.
Taught in
Related terms
- allele — An allele is one version of a gene; a person carries two for most genes, one on each chromosome of a homologous pair, and the pair is the genotype.
- chromosome — A chromosome is one long DNA molecule wound around histone proteins, and a human body cell carries 46 of them, in 23 pairs.
- meiosis — Meiosis is the division that makes gametes: two divisions after one DNA replication turn one diploid cell into four haploid cells.
Source: The biology guide in this course: its genetics definitions follow the National Human Genome Research Institute's Talking Glossary of Genomic and Genetic Terms, and its process descriptions follow the US National Cancer Institute's SEER Training Modules. Both are US federal government material, not subject to copyright in the United States. The microbiology entries — the bacterial cell, the Gram stain and the chain of infection — were written for this course from the infection-control guidance the biology guide's own source list names (US Centers for Disease Control and Prevention), which the genetics glossary does not cover. The definitions above are written for this course in our own words. (NHGRI Talking Glossary accessed 2026-10-26; definitions written 2026-10-27; the CDC basis for the microbiology entries — Principles of Epidemiology in Public Health Practice, third edition — accessed 2026-10-28, the date the biology guide's own source list records)