biology paper 2

• Immigration


  The movement of individual organisms into a particular area to increase population size
• Emigration


  The movement of individual organisms away from a particular area decreasing population size
• What are density independent factors

  Factors that effect the whole population regardless of its size

  earthquakes volcano fires and storms
• Arguments for animal cloning

  • Artificial twinning allows high yielding farm animals to produce more offspring than normal reproduction
  • articifial twinning ensures success of sire passing on desirable genes to be determined
  • SCNT enables GM embryos to be replicated and develop
  • SCNT allows cloning of specific animals eg specific pets or race horses
  • SCNT has the potential to enable endangered rare or even extinct animals to reproduce
• Arguments against animal cloning

  • SCNT is a very inefficient process
  • many cloned animal embryos fail to develop and miscarry or produce malformed offspring
  • many animals produced have shortened lifespans
  • SCNT has been relatively unsuccessful in increasing populations of rare or extinct organisms
• GM crops


  • Pest resistant
  • Disease resistant
  • Herbicide resistant
  • Extended shelf life
  • Increased nutritional value
• Pest resistant crops


  Reduce the amount of pesticides spraying which protects environment and increases yield
• Pest resistant crops


  Insects may become resistant and insect-sting predators might be damaged by the toxins
• Disease resistant crops


  Increases yield
• Disease resistant crops


  Transferred genes may spread to wild populations and cause problems
• Herbicide resistant crops


  Reduce competition and increase yield
• Herbicide resistant crops


  Biodiversity may be reduced
• Extended shelf life crops


  Reduces commercial value and demand of crop
• Increased nutritional value crops

  People may be allergic to different proteins made in crops
• Immobilised enzymes


  • Penicillin acylase used to make semi-synthetic penicillins
  • Glucose isomerase used to produce fructose from glucose
  • Lactase used to produce lactose-free milk
  • Aminoacylase used to produce pure samples of L-amino acids for pharmaceuticals and food
  • Glucoamylase used to complete the breakdown of starch to glucose syrup
  • Nitrile hydratase used in the plastics industry to produce acrylamide much cheaper and 99% yield
• importance of penicillin scales

  Bacteria is becoming resistant to natural penicillins so they are no longer effective but are still vulnerable to semi synthetic
• Importance of immobilised glucose isomerade

  Fructose is sweeter than glucose and is used as a sweetener in food industries. Turns glucose into sweet profitable fructose
• Immobilised lactase


  Converts lactose to glucose and galactose making sugar free milk