March 1902, William Bateson signed his dissertation "Mendel's Principles of Heredity", Bateson needed to read Mendel's paper during the brief journey in London in 1900 which would change profoundly his world. Bateson had a new mission in life. He understood that the mystery of inheritance had been solved. He soon became a relentless apostle of Mendel's laws of inheritance. A few years later in 1905, Bateson coined the term genetics, and the genetics revolution had begun. Mendel proposed that the factors that control traits act like particles rather than fluids and that these particles do not blend together but are passed intact from one generation to the next. Later, the first compelling experimental evidence was that genes are made of deoxyribonucleic acid (DNA). This book is a reading on the structure and function of the DNA and is as a mission towards William Bateson idea.