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.
RNA nucleotides are defined by the sugar ribose, and contain a slightly different set of nitrogenous bases: adenine, guanine, cytosine, and uracil. RNA molecules do not contain thymine. Unlike DNA, RNA is usually present in a single-stranded form.NA contains deoxyribose nucleotides while RNA contains ribose nucleotides. DNA is more stable than RNA because of the reduction in reactive oxygen atoms. A 5-carbon sugar (ribose or deoxyribose) forms the central molecule in a nucleotide.