Following fertilisation, the single cell splits into two and then into four cells and so on. This process is known as Cell Division. First, cells copy their genetic information or “genes” and these are then shared equally between the two new cells. Genes are made of DNA and are located in the centre of the cell in the nucleus. During cell division they appear as finger-like structures called chromosomes.

(above) Top cell is just about to divide , while the lower cell is dividing, separating its chromosomes (pink) equally into two groups. Film Cedit: Jason Swedlow, University of Dundee Images © Wellcome Images

There are multiple steps to cell division. Chromosomes first condense (prophase), then matching pairs of chromosomes line up along the middle of the cell (metaphase). Chromosomes are then attached to microtubules which form a spindle-like network at either end of the cell. Image © Wellcome Images

Microtubules now pull the chromosomes apart (anaphase). The cell then splits into two with each new cell containing an identical set of genes (telophase). Find out more: About genes, DNA and chromosomes A free key textbook account of the cell cycle - Chapter 18 of Essential Cell Biology Key labs that work on Cell Division: Professor Tomo Tanaka, University of Dundee Jason Swedlow, University of Dundee Kim Nasmyth, University of Oxford Read a scientific article A review of the mechanics of mitosis

Anaphase dress: Silk, mirrored paper, viscose jersey The floating breastplate shows pairs of chromosomes pulling apart as a cell divides. Red fringing is a reminder of the spindles along which the chromosomes are drawn. Drawing 1997 Copyright Helen Storey