BIOL 1202 Chapter : BIOL 1202 Chapter 25 Outline
Document Summary
Chapter 25 outline: the history of life on earth. Conditions on early earth made the origin of life possible. Direct evidence of life on early earth comes from fossils of microorganisms that are about. There is scientific evidence that earth and the other planets of the solar system formed about 4. 6 billion years ago, condensing from a vast cloud of dust and rocks that surrounded the young sun. The presence of small organic molecules, such as amino acids and nitrogenous bases, is not sufficient for the emergence of life as we know it. Every cell has a vast assortment of macromolecules, including enzymes and other proteins and the nucleic acids that are essential for self-replication: protocells. All organisms must be able to carry out reproduction and energy processing (metabolism): life cannot persist without both of these functions. Dna molecules carry genetic information, including the instructions needed to replicate themselves accurately during reproduction.
