A human being is made up of between fifty and seventy trillion cells, the majority of which are formed by mitosis; the average human male produces over a hundred million new sperm a day by the process of meiosis; every cell in a multi-cellular organism contains exactly the same DNA (with the exception of gamete cells and red blood cells) as a result of the process of mitosis. It can't be argued against, that cell division is one of the most important processes in biology. I wanted to write a book that explained clearly the function of mitosis and meiosis, the two different types of cell division; and how they happen. A lot of the other books I had read seemed to rely on diagrams to explain the differences; but often didn't seem to clarify it properly. So, I hope through reading this book you will come to understand the function and processes of mitosis and meiosis really clearly; and that this will increase your overall understanding and enjoyment of biology!