BIOLOGY 2

• Genetic Engineering


  A process that uses laboratory-based technologies to alter the DNA makeup of an organism

  
• Steps in Genetic Engineering

  1. Isolation of DNA fragments from a donor organism

  2. Insertion of an isolated donor DNA fragment into a vector genome

  3. Growth of a recombinant vector in an appropriate host

  
• Vector Genome


  A DNA molecule (often plasmid or virus) that is used as a vehicle to carry a particular DNA segment into a host cell as part of a cloning or recombinant DNA technique

  
• Host Organism


  The organism into which the recombinant DNA is introduced

  
• Bacteria are commonly used as host cells for making copies of DNA in the lab because they are easy to grow in large numbers

  
• Recombinant DNA (rDNA) technology


  The process of joining DNA molecules from two different sources and inserting them into a host organism, to generate products for human use

  
• DNA Isolation


  1. Enzymatically controlled process where the plant or animal cells are treated with certain enzymes to extract the desired DNA in its purest form, free of extraneous macromolecules

  2. Addition of Ethanol causes the DNA to precipitate out as fine threads

  
• Enzymes used in DNA Isolation

  • Lysozyme - to break bacterial cell wall
  • Cellulase - to break plant cell wall
  • Chitinase - to break fungal cell wall
  • Ribonuclease - removes RNA
  • Protease - removes proteins (such as histones that are associated with DNA)
• Agarose Gel Electrophoresis


  A technology that allows digested DNA fragments to be separated and snipped out
• Restriction Enzymes


  Act as molecular scissors that cut DNA at specific locations
• Polymerase Chain Reaction (PCR)


  A method of making multiple copies of a DNA sequence using the enzyme DNA polymerase

  
• DNA Ligation


  The process of joining the cut DNA fragment and the cut vector using the enzyme DNA ligase
• Recombinant DNA


  The hybrid DNA molecule resulting from the joining of the interest molecule and the vector DNA molecules
• Transformation


  The process of adding the recombinant DNA to the recipient host cell

  
• Bacterial cells have a hard time accepting foreign DNA, so they are given treatments to make them 'capable' of accepting new DNA</b>

  
• Small volumes of cell cultures will not yield a large amount of recombinant protein, so large-scale production is necessary to generate products that benefit humans
• Geologic Time Scale


  Divides up the history of the earth based on life-forms that have existed during specific times since the creation of the planet
• Divisions of the Geologic Time Scale

  • Eons
  • Eras
  • Periods
  • Epochs
• Eons of the Geologic Time Scale

  • Hadean - eon without fossils
  • Archaean - cooling of Earth; life starts to flourish
  • Proterozoic - "earlier life"; eukaryotes (oxygen)
• Formation of Early Life on Earth

  1. Formation of Earth, oceans, and continental crusts

  2. Formation of Biomolecules (Amino Acids, RNA, Plasma Membranes)

  3. Formation of Protocells (Fatty acids + DNA molecules)
• Last Universal Common Ancestor (LUCA)

  Prokaryotic, anaerobic, lives in extreme environments
• Stromatolites


  Rocky layered structure that is formed when prokaryotes trap minerals and sediments
• Photoautotrophs


  Organisms that harness energy from the sun for metabolism
• Photoautotrophs increased the amount of oxygen in the atmosphere
• Solar radiation acted upon oxygen, forming the ozone layer
• Bacteria engulfing other bacteria gave rise to the organelles mitochondria and chloroplasts
• Ediacaran Period


  635 mya to 541 mya, new addition to the geologic time scale, named for the fossil deposits in Ediacara Hills in South Australia, saw the appearance of multicellular life-forms (Sponges, Jellyfish, and Worms)
• End-Ediacaran Extinction was caused by reduced global oceanic oxygen availability
• Phanerozoic Eon


  The current geologic eon in the geologic time scale, during which abundant animal and plant life has existed
• Paleozoic Era


  "The era of old life", lasted from 544 to 245 mya and is divided into six periods
• Evolutionary Radiations


  • Periods of evolutionary change in which groups of organisms form many new species, usually occurring at the end of mass extinctions, in groups with evolutionary innovations
• Cambrian Period


  • Saw the emergence and rapid diversification of invertebrates, with major animal groups arising, including small vertebrates (cartilaginous fishes), sponges, and trilobites
• Ordovician Period


  • Saw the adaptive radiation of the animal phyla, with marine large predators like sea stars and nautiloids, and the first fossils of land-dwelling plants
• Silurian Period


  • First period with fossils of land-dwelling plants, suggesting the colonization of land had begun, with the first known terrestrial organisms being spore-bearing structures related to today's liverworts
• Devonian Period


  • Saw the first appearance of trilobites, brachiopods, and the first jawed fishes, as well as the emergence of the first terrestrial vertebrates and plants

  
• Tiktaalik roseae


  Transitional form between fishes and tetrapods, with fish features like scales, fins, and gills, and tetrapod features like a movable neck and rib cage
• Carboniferous Period


  • Saw the evolution of winged insects, the diversification of seed plants, and the rise of giant arthropods and the adaptive radiation of tetrapods, with forests dominated by giant tree ferns and horsetails
• Permian Period


  • Saw the formation of the supercontinent Pangaea and the rise of the synapsids, the largest terrestrial vertebrates, which gave rise to the lineages of reptiles and mammals
• Triassic Period


  • The "Age of Reptiles", with sea level rises covering continental regions in shallow seas, and the appearance of the first mammals
• Jurassic Period


  • Saw the adaptive radiation in the reptilian lineage, giving rise to crocodiles and dinosaurs, and the diversification of invertebrates