How like begets like #002
They are probably not designed for a chemist or a physicist.
How is the shape of the nose or the color of the hair encrypted there, passed down from generation to generation? More than a hundred years ago, Swiss biochemist Friedrich Miescher isolated an unknown substance from the cell nucleus. He called it a nuclein. Ten years later, it turned out that not the entire nucleus consists of nuclein, but only chromosomes — the staining corpuscles that are present in every cell, or rather, in its nucleus. A few more years later, it became clear that chromosomes are the very organ of the cell that is responsible for transmitting hereditary information. And already in 1885, several scientists simultaneously made a guess that was far ahead of its time: the nuclein is a genetic record. And after that, facts began to accumulate that clearly contradicted the magnificent idea. It turned out that the nuclein content in the nucleus does not remain constant — it is either low or high. Sometimes it disappears altogether. Naturally, this should not happen with hereditary material. Friedrich Miescher himself was very skeptical about this role of the nuclein. It was only much later, in 1948, that the amount of nuclein (by this time it had become known as deoxyribonucleic acid, DNA) in cell nuclei was precisely determined. It turned out that the content of deoxyribonucleic acid in the cell is always constant (it doubles only before division). In Miescher's time, nuclein was determined by staining. And, as it turned out, he is not always able to perceive the dye. This explained his "disappearance". Direct evidence that it is deoxyribonucleic acid that stores records of all the body's features appeared a little earlier. At first, it was the amazing experiments of microbiologist Griffiths. He worked with pneumococcus, a bacterium that causes severe illness in laboratory animals. A characteristic feature of this microbe is the presence of a mucous membrane, capsule. But in laboratory cultures, it was not uncommon to come across "naked" bacteria stripped of these clothes. No wonder — there are, for example, hornless cows. But if a cow deprived of horns gives normal milk, then uncapsulated pneumococcus does not cause disease — it is harmless.
Griffiths came up with the idea of testing whether harmless, non-virulent microbes could be turned back into normal ones. A large batch of mice was divided into four groups. 1xBet offers an exclusive welcome bonus for new customers who register using the 1xbet promo code to claim an exclusive bonus in total of €130. The bonus is available to new users registering an account with 1xbet. This already excellent deal is made even more irresistible by the fact that users can receive a 100% first deposit match bonus up to 130$.