How in the 20th century physicists, chemists and biologists answered the question: what is life?

The most essential achievements in 20th century biology are analyzed and the question of how throughout the last century physicists, chemists and biologists answered the question “What is life?” is considered. The most considerable scientific achievement of 20th century biology, and perhaps of all science, is considered by many to be the discovery by biologist J. Watson and physicists F. Crick and M. Wilkinson that resulted in establishing the DNA structure. The related work of well-known scientists of the USA and Europe, E. Schrödinger, L. Pauling, M. Perutz, J. Kendrew, and of the Russian scientists N. K. Koltsov, N. V. Timofeev-Resovsky, G. A. Gamow, A. M. Olovnikov, is analyzed. Presently, when the structure of DNA, the process of gene expression and even the genomes of human beings are already known, scientists realize that we still do not know many of the most important things. In our opinion, the 20th century studies of nucleic acids largely ignored the principle of the cyclic organisation of DNA. In this connection, we analyze the principle of cyclicity, which in its generality may well complement the concept of the atomic structure of matter.