Rheumatoid Arthritis Symptoms In Women. Disorder that is believed to result from an autoimmune process in which the body's immune system attacks itself. It is a system-wide disease that usually last for many years. In some patients, RA affects such organs as the heart, lungs, and eyes.
The first organic molecules formed about 4 billion years ago. This may have happened when lightning sparked chemical reactions in Earthâs early atmosphere. RNA may have been the first organic molecule to form as well as the basis of early life. Explore More Use the time slider in this resource to answer the questions that follow.
Both DNA and RNA are known as nucleic acids. They have been given this name for the simple reason that they are made up of structures called nucleotides. Those nucleotides, themselves comprising a number of components, bond together to form the double-helix first discovered by the scientists James Watson and Francis Crick in 1956.