VMBO Year 3 · Organs and cells · Section 1.5
Cell division: mitosis
New cells for growth and repair
Your body produces large numbers of new cells every day through ordinary cell division, involving mitosis. This allows growth, replaces damaged or worn-out cells and helps wounds heal. One parent cell divides to form two daughter cells, usually with the same genetic information as the original cell.
How does ordinary cell division work?
This course describes three stages: nuclear division, division of the cytoplasm and subsequent cell growth. Before mitosis, the DNA is copied, so each chromosome consists of two identical sister chromatids. The chromosomes then become tightly coiled, shorter and thicker: this is condensation. During nuclear division, the sister chromatids separate. Each new nucleus receives a complete set, forming two genetically identical nuclei unless a copying error has occurred.
From nuclei to cells
During cytokinesis, the cytoplasm divides, producing two separate daughter cells, each surrounded by a cell membrane. The chromosomes uncoil and can no longer be distinguished individually. Afterwards, the daughter cells grow by making more cytoplasm and other cell components.
Main features of mitosis
- One parent cell gives rise to two daughter cells.
- Each daughter cell normally has the same chromosome number and genetic information as the parent cell.
- The genetic information is therefore maintained during growth and repair.
Glossary
- Cytokinesis
- Division of the cytoplasm, separating the cell into two daughter cells.
- Daughter cells
- The new cells formed when a parent cell divides.
- Ordinary cell division
- Division producing two cells with the same genetic information as their parent cell, involving mitosis and cytokinesis.
- Nuclear division
- The stage in which copied chromosomes are separated and two nuclei form.
- DNA replication
- Copying DNA before division, producing two sister chromatids for each chromosome.
- Mitosis
- Nuclear division that distributes an equivalent set of chromosomes to each of two new nuclei.
- Parent cell
- A cell that divides to produce daughter cells.
- Cell growth
- An increase in a cell's size as it makes more cytoplasm and other components.
- Condensation
- The tightening and coiling of chromosome material, making chromosomes shorter, thicker and visible during division.