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 introduced to the West in the Holy Roman Empire by Johannes Gutenberg, around 1440.Gutenberg, a goldsmith by profession, devised a hand mould to create metal movable type, and adapted screw presses and other existing technologies, to create a printing system.ypically used for texts, the invention of the printing press is widely regarded as one of the most influential events in the second millennium, ushering in the period of modernity. Movable-type presses using cast ceramics were employed in China from the early years of the last millennium.