Cell theory: Why is it important?

Nobel prize winner, Sir Paul Nurse, thinks there are five big ideas in biology. He suggests that cell theory is the first of these. During a 2006 tour of New Zealand, he explained why cells are so important.

Transcript

Sir Paul Nurse: The idea of the cell, the cell doctrine, is that all life is composed of cells. That is, the cell is the basic unit of life, structural unit of life. Secondly, that the cell is the simplest unit exhibiting the characteristics of life. That is, it’s the simplest entity which exhibits the characteristics, the phenomena, that we associate with life.

Cell theory - This is crucial for us understanding biology because cells form the basis of all life. We can have unicellular organisms, like bacteria, like yeasts. [And] cell division, the division of a cell from one, to two, to four, forms the basis of growth and development of all living things. When it goes wrong, as in cancer, then of course it’s crucial for disease. And we can see its importance ... this is a picture of an early mammalian embryo - all those little dark spots there represent single cells. It's just to emphasise that each one of us is made up of billions of cells, and you can see easily in a foetus. But we ourselves are made up of billions of cells generated by these successive rounds of division. This [picture] is a mammalian unfertilised egg being bombarded with many sperm. So everyone of you in this room once was like this. And this is a single cell, and that is why we should be interested in cells and of course the cell theory.