BSC2011C Final Review Unit 1 Review Ch. 25, 22, 23, 24, 26, 19, 27 Ch. 25 1. Life is metabolism and heredity. Metabolism is the mechanism that creates order and complexity from chaos, by acquiring and expending energy. Heredity is the ability of an organism to copy itself and it is broken down into: i. Multiplication, ii. Inheritance, iii. Variation. 2. DNA codes via RNA for 20 of naturally occurring amino acids. Amino Acids are the building blocks of proteins and bodies. DNA stores and transmits hereditary information, but proteins do most of the work. DNA IS THE UNIVERSAL DIGITAL CODE FOR LIFE. To replicate and synthesize proteins, DNA relies on the pre-existence of protein molecules and RNA molecules. 3. RNA is the bridge between DNA and proteins, via mRNA for transcription and rRNA for translation. Thus, RNA can survive on its own while DNA relies on the existence of RNA and proteins, with them DNA is helpless. 4. The 4 points of “first life” are: 1. The Abiotic (non-living) synthesis of small organic molecules, such as amino acids and nucleotides. 2. The joining of these small molecules into macromolecules, including proteins and nucleic acids. 3. The packing of these molecules into “protobionts,” droplets with membranes hat maintained an internal chemistry different from that of their surroundings. 4. The origin of self-replicating molecules that eventually made inheritance possible. 5. The first cells to develop occurred in this order: Monomers > Polymers > Protobionts > RNA ‘world’ > DNA protobionts > first cell. 6. Fossils are the evidence of life and evolution. Organisms trapped in sediment > remain mineralized with hard and soft parts. 7. Fossils can be dated by two methods: Radiometric dating & Magnetism. In Radiometric dating, the age is based on the decay of radioactive isotopes. A radioactive “parent” isotope decays to a “daughter” isotope at a constant rate. The rate of decay is expressed by the half-life, the time requires for 50% of the parent…
