Chest pain is always an alarming symptom since it usually raises the fear of heart disease. And because chest pain may indeed be a sign of angina or of some other heart problem, it is always a good idea to have it checked out. But heart disease is only one of the many types of conditions that can produce chest pain.
Concept 27 Mutations are changes in genetic information. Hermann Muller received the 1946 Nobel Prize in Physiology or Medicine for his work on mutations induced by X-rays. Seymour Benzer used genetics to prove that mutations were caused by changes in the DNA sequence.
Conservation of mass. Russian scientist Mikhail Lomonosov discovered the law of mass conservation in 1756 by experiments, and came to the conclusion that phlogiston theory is incorrect. Antoine Lavoisier's discovery of the Law of Conservation of Mass led to many new findings in the 19th century. Joseph Proust's law of definite proportions and John Dalton's atomic theory branched from the discoveries of Antoine Lavoisier.