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.
The printing press was one of the most significant inventions of the Middle Ages. It was invented in the mid-15th century (during the Renaissance period) by a German goldsmith named Johannes Gutenberg.