exam genbio 2

• genetic engineering - the artificial manipulation, modification, and recombination of DNA or other nucleic acid molecules in order to modify an organism or population
• DNA OR DEOXYRIBONUCLEIC ACID - is a long molecule that contains our unique genetic code.
• recombinant - a chromosome, cell, organism, etc. the genetic makeup of which results from recombination
• recombinant dna technology - the joining together of DNA molecules from different organisms and inserting it into a host organisms to produce new genetic combinations that are of value to science, medicine
• genome - an organism's complete set of genetic instructions
• our genome is approximately 3,000,000,000 base pairs long and is packaged into 23 pairs of chromosomes
• biotechnology - includes a wide range of process
• a general outline of recombinant dna may be given as follows;

  cutting or cleavage of DNA by restriction enzyme

  selection of an appropriate vector or vehicle

  ligation (join together)

  transfer of the recombinant plasmid into a host cell
• carbon-14 - radioactive isotope of carbon
• fossils - are evidences of organisms that lived in the past
• catgeories of fossil types; trace fossil, mold and cast, replacement, petrified or permineralized, amber, original material
• trace fossil - any indirect evidences left by an organism
• mold and cast - a mold is an impression of an organism. a cast is a mold filled with sediment
• replacement - the original material of an organism is replaced with mineral crystals that can leave detailed replicas of heard or soft parts
• petrified or permineralized - empty pore spaces are filled in by minerals, such as petrified wood
• amber - preserved tree saps traps an organism
• original material - mummification or freezing
• six ways of fossilization - unaltered preservation, permineralization/petrification, replacement, carbonization or coalification, recrystalization, authigenic preservation
• unaltered preservation - small organism o part trapped in amber, hardened plant sap
• permineralization/petrification - the organic contents of bone and wood are replaced with silica, calcite or pyrite, forming a rock-like fossils
• replacement - hard parts are dissolved and replaced by other minerals like calcite, silica, pyrite, or iron
• carbonization or coalification - the other elements are restored and only the carbon remained
• recrystalization - hard parts are converted to more stable minerals or small crystals turn into larger crystals
• authigenic preservation - molds and casts are formed after most of the organism have been destroyed or dissolved
• dating fossils; relative dating, absolute dating
• relative dating - based upon on the study of layer of rocks.
• relative dating; law of superposition, low of original horizontality, law of cross-cuutting relationships
• law of superposition - sedimentary layers are deposited in a specific time- youngest on top, oldest at bottom
• law of original horizontality - deposition of rocks happen horizontality - tilting, folding or breaking happened recently
• law of cross-cutting relationships - if am igneous intrusion or a fault cut through existing rocks
• absolute dating - determines the actual age of the fossil
• geologic time scale - is the record of the geologic history of earth
• geological time scale hierarchial; eon, era, period, epochs
• the last column, which indicateds millions of years ago, represented by MA which means mega-annum
• eon - the largest division of the geologic time scale.
• three major eons; archean, proterozoic, phanerozoic eons
• era - is hunderd of million years long
• three major eras - paleozoic, mesozoic, cenozoic
• mass extinctions - mark the boundaries between the eras
• period - is tens of millions of years long