Cloning and biotech

• How can we produce natural clones of plants

  vegetative propagation

  • part of the plant is separated then develops new plant that is genetically identical
• How should a plant cutting be taken for cloning?

  stem is cut between the leaf and nodes

  • replanted and allowed to grow sometimes with the use of plant hormones
• How can we produce artificial clones of plants

  Tissue culture = sample placed on various mediums to encourage cell division and shoot growth

  Micropropagation = material produced from tissue culture is rapidly multiplied to produce large numbers of plants
• Evaluate the use of artificial plant cloning in agriculture

  + large number of plants can be produced regardless of weather conditions

  • reduces genetic variation, making them susceptible to disease
• Give an example of natural cloning in animals

  Monozygotic twins - embryo splits during development to produce two genetically identical individuals
• How can we produce artificial clones?

  • Somatic cells nuclear transfer = differentiated cell from parent fused with an enucleated egg cell
  • Embryo splitting = same process by which twins form performed artificially
• Give arguments surrounding cloning in animals

  + quick process suited to the growing population of earth

  + can preserve endangered species

  • cloned animals often suffer from health problems
  • low genetic diversity
• Why are microorganism suited for use in biotechnological processes?

  • rapid growth in a variety of environmental conditions
  • can be genetically engineered
  • reduces use of chemicals beneficial to the environment
• Give some ways microorganisms are used in biotechnological processes

  • food ; baking, brewing, yogurt, cheese
  • medicine; penicillin, insulin
  • environmental; removing pollution
• Give advantages of using microorganisms to produce food for human consumption 


  + production rate easily varied

  + not dependent on climate

  + long-lasting

  + uses waste products
• Give disadvantages of using microorganism to produce food for human consumption

  • lack of flavour
  • proteins must be isolated and purified
  • contains different amino acids to animal proteins
• Describe the technique that should be used to culture microorganisms

  aseptic technique; everything must be kept completely sterile so that no unwanted microorganisms are present in the culture
• Summarise the three steps of growing microorganisms

  1. sterilisation; part of the aseptic technique
  2. inoculation; microorganisms introduced to agar plate by streaking, seeding or spreading
  3. incubations; warm enviornment for 24-48 months
• batch fermentation


  closed environment, competition for resources, maintain culture in stationary phase, easy to set up less efficient
• continuous fermentation 


  products continually removed maintains culture in log phase, difficult to set up more efficient
• How are the growth conditions manipulated to maximise yield?

  • temperature maintained at optimum
  • sufficient nutrient supply
  • aerobic conditions to prevent products of anaerobic respiration
  • pH kept constant to maximise enzyme activity
• lag phase 


  cells increase in size and take in water. Population constant
• log phase 


  cell divide. Population increases exponentially
• stationary phase 


  nutrient level decrease, slowing growth rate. Population stabilizes
• death phase 


  toxic metabolites increase to a point that kills cells. Population declines
• population graph

  
• Bacterial growth formula

  N= N0 x 2n

  N = number of bacteria in the population

  N0 = number of bacteria in the population at the beginning

  n = number of divisions
• what is an immobilised enzyme?

  An enzyme attached to an inert material in order to restrict its movement and hold it in place during a reaction so that it can be reused
• Give methods of immobilising enzymes

  1. bonding = enzyme binds with support ionically or covalently
  2. entrapment = enzymes placed in a semi-permeable material that allows diffusion of the substrate and product
  3. membrane separation = partially permeable membrane separates enzyme from substrates
• gives uses of immobilised enzymes

  • glucose to fructose conversion
  • semi-synthetic penicillin production
  • Lactose to glucose/galactose conversion
  • pure samples of amino acids
  • dextrin to glucose conversion
• Evaluate the use of immobilised enzymes

  + product is not contaminated by enzyme, so does not need to be purified

  + enzymes can be reused

  + enzymes are protected from harsh environment

  • expensive
  • reaction rate slower as enzymes cannot move