Answer: Both deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are made up of nucleotides which consist of three parts: 1  Nitrogenous Base. 2  Purines and pyrimidines are the two categories of nitrogenous bases.3  Pentose Sugar. 4  In DNA, the sugar is 2'-deoxyribose. 5  Phosphate Group. 6  A single phosphate group is PO 4 3- .nswer: Both deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are made up of nucleotides which consist of three parts: 1  Nitrogenous Base. 2  Purines and pyrimidines are the two categories of nitrogenous bases.
AT A GLANCE: In 1440, German inventor Johannes Gutenberg invented a printing press process that, with refinements and increased mechanization, remained the principal means of printing until the late 20th century.
Lesson Summary. Johannes Gutenberg was a German blacksmith and inventor known for developing the first mechanical moveable type printing press. Gutenberg was born in Mainz, Germany, around 1400. His printing press is one of the most important inventions of human history and widely considered the most important invention of the modern era.