AP BIOLOGY

Detailed explanation-1: -The theory suggests these reactions then led to the creation of molecules such as DNA and RNA, which subsequently became part of a self-replicating system which would ultimately become life.

Detailed explanation-2: -Meteorite Amino Acid Analyses. The predominant amino acids detected were glutamic acid and glycine, with lesser amounts of aspartic acid, serine, alanine, -alanine, and -amino-n-butyric acid (-ABA).

Detailed explanation-3: -Scientists confirmed in 1971 that the Murchison meteorite contained amino acids, primarily glycine, and that those organic compounds likely came from outer space (SN: 3/20/71, p. 195). In the decades since, amino acids and other chemical precursors to life have been uncovered in other fallen space rocks.

Detailed explanation-4: -The Big Bang Theory is the most accepted theory regarding the origin of the planet earth and the existence of different life forms on it. According to this theory, the universe is a result of a massive explosion which occurred 20 billion years ago.

Detailed explanation-5: -Some scientists have long suggested that a substantial fraction of the organic compounds that were the precursors to amino acids-and perhaps some amino acids themselves-on early Earth may have been derived from comet and meteorite impacts.