Cell Theory states that cells come from pre-existing cells. What does this mean? Our body is made up of billions of cells, and all of them originate from only TWO basic cells - the sperm and egg. To get from 2 cells to a billion, these 2 cells divide many many MANY times. A lot of our cells (especially stem cells) continue to divide during our lives, for example, to replace dying cells or repair injured tissue.
Sometimes cells go a little hay-wire and start to divide uncontrollably. This can occur in any organ or tissue, and the result is a cancerous tumour.
To duplicate, cells go through a cell cycle which is divided into a number of stages: interphase, mitosis and cytokinesis.
Sometimes cells go a little hay-wire and start to divide uncontrollably. This can occur in any organ or tissue, and the result is a cancerous tumour.
To duplicate, cells go through a cell cycle which is divided into a number of stages: interphase, mitosis and cytokinesis.