Mitosis

Lore & Background

Numerous descriptions of cell division were made during the 18th and 19th centuries, with various degrees of accuracy. A few years later, he discovered and described mitosis based on those observations. However, the term 'mitosis' is also used in a broad sense by some authors to refer to karyokinesis and cytokinesis together. Presently, 'equational division' is more commonly used to refer to meiosis II, the part of meiosis most like mitosis.

Reader's Guide

Mitosis is fundamental to eukaryotic life, as it produces genetically identical daughter cells, maintaining genetic stability across cell generations. The process is divided into stages: preprophase (specific to plant cells), prophase, prometaphase, metaphase, anaphase, and telophase. During mitosis, chromosomes condense and attach to spindle fibers that pull one copy of each chromosome to opposite sides of the cell. The result is two genetically identical daughter nuclei. Errors in mitosis can result in tripolar or multipolar mitosis, leading to non-viable embryos, mitotic catastrophe, apoptosis, or mutations that can cause certain types of cancers. Mitosis varies between organisms: animal cells generally undergo open mitosis (nuclear envelope breaks down), while fungal cells undergo closed mitosis (chromosomes divide within an intact nucleus). Most human cells are produced by mitotic cell division, with important exceptions including gametes, which are produced by meiosis. Prokaryotes divide by binary fission. The study of mitosis remains central to understanding cell biology, development, and disease.

Did You Know?

• Mitosis is preceded by the S phase of interphase, during which DNA replication occurs.
• An error in mitosis can result in tripolar or multipolar mitosis, producing three or more daughter cells instead of the normal two.
• Animal cells generally undergo open mitosis, where the nuclear envelope breaks down before chromosomes separate, while fungal cells undergo closed mitosis.