cloning and biotech

• Clone


  Genetically identical copies of both parent organism and each other
• Natural cloning in plants

  1. Genetically identical offspring via mitosis

  2. Vegetative propagation
• Natural cloning in plants


  • Bulbs (e.g. daffodil)
  • Runners (e.g. strawberry)
  • Rhizomes (e.g. marram grass)
  • Stem tubers (e.g. potato)
• Natural cloning in horticulture


  1. Use a non-flowering stem

  2. Make a diagonal cut which increases the surface area

  3. Dip the shoot into rooting hormone powder

  4. Put it in compost and shelter for a few days in a greenhouse
• Advantages of natural cloning in horticulture


  • Large number of trees grow in one area -> larger supply
  • Grow close together -> easier to harvest
  • Dense patches of trees -> woodland animals -> ecotourism
• Disadvantages of natural cloning in horticulture

  • No genetic variation -> no natural selection
  • Cannot stop growth in unwanted places
• Artificial cloning in plants (micropropagation)

  1. Take small tissue sample from plant (explants)

  2. Place explant in sterile culture medium with plant hormones

  3. Cells proliferate -> callus

  4. Transfer new shoots to new medium with different hormones and nutrients

  5. Stimulate plantlets and then pot in compost
• Advantages of artificial cloning in plants

  • Rapid production of large number of plants
  • Meristem -> disease free
  • Produces seedless plants
  • Costs reduced as harvest at same time
• Disadvantages of artificial cloning in plants

  • Monoculture -> low genetic diversity
  • Expensive process
  • Vulnerable to infection
  • Source with virus -> all clones infected
• Artificial cloning in animals (artificial twinning)


  1. Male cow with best characteristics has sperm taken

  2. Sperm placed in female cow with the best characteristics

  3. Sperm and egg are inseminated artificially

  4. Splitting the ball of cells to form identical embryos

  5. Embryos split into further balls of totipotent cells (left to develop for 6 days)

  6. Embryos placed in the surrogate mother
• Artificial cloning in animals (somatic cell nuclear transfer)

  1. Nucleus removed from somatic cell

  2. Egg cell removed from an organism of the similar species

  3. Nucleus from egg cell is removed

  4. Remove nucleus from donor cell

  5. Nucleus from somatic cell is inserted into egg via electric shock

  6. New cell divides -> an embryo

  7. Embryo inserted into uterus of animal
• Advantages of artificial cloning in animals

  • Rare, endangered animals to be reproduced
  • Good farm stock -> agriculture
  • Clones' specific animals
  • GM animals can be reproduced
• Disadvantages of artificial cloning in animals

  • Ethical + animal welfare issues
  • May not remain healthy long term
  • May not adapt to environmental changes
  • Many eggs to produce single clone (many embryos fail / malform)
• Indirect food production


  • Microorganisms produce another food (byproduct)
  • Must require ideal conditions
  • Microorganisms' ideal conditions may cause disease/food to go bad
• Indirect food production - Baking

  1. Yeast with sugar + water -> anaerobic respiration

  2. CO2 from Krebs cycle and would create fermentation bubbles
• Indirect food production - Brewing

  1. Yeast -> anaerobic respiration

  2. Yeast produces ethanol from starch and sugars -> alcohol
• Indirect food production - Cheesemaking

  1. Bacteria feed on lactose

  2. Changes texture + taste

  3. Milk pasteurised + homogenised

  4. Mixed with bacteria culture to separate solid curds and liquid whey
• Indirect food production - Yoghurt making


  1. Bacteria forms ethanol + lactic acid

  2. Produces polymers

  3. Lactobacillus clots milk -> thickens
• Direct food production


  Fungi + egg whites -> Quorn
• Advantages of using microorganisms for food

  • Reproduce fast, produce protein faster
  • High protein, little fat
  • Can use wide variety of waste materials -> less costs
  • Not dependant on weather so can meet demands
• Disadvantages of using microorganisms for food

  • Can produce toxins at non-optimum temp
  • Need separation from nutrient broth + processed
  • Sterile conditions required -> higher costs
  • Protein needs purification (no contaminants)
  • Little natural flavour + needs additives
• Penicillin production

  1. Penicillium fungi produces penicillin which kills bacteria

  2. Requires high oxygen + nutrients in bioreactor
• Insulin production


  GM bacteria
• Bioremediation


  Use of organisms to remove/neutralise pollutants from a contaminated site eg soil or water
• Natural organisms for bioremediation

  • Naturally break down organic material -> CO2 + H2O
  • Can break down pollutants (e.g crude oil, sewage)
• GM organisms for bioremediation


  • Developing to break down contaminants not naturally encountered
  • GM bacteria can remove mercury contamination
• Inoculating broth


  1. Suspension

  2. Stopper flask with cotton wool -> no contamination

  3. Incubate + shake -> aerate broth with oxygen
• Inoculating agar


  1. Wire inoculating loop sterilized

  2. Dip in bacterial suspension

  3. Petri dish zig-zag streak

  4. Tape lid
• Growth of colonies


  1. Lag phase - adapting to environment, synthesizing enzymes required

  2. Log phase - bacterial reproduction rate at maximum

  3. Stationary phase - total growth rate = 0, number new cells = number dying cells

  4. Decline phase - death rate increasing
• Limiting factors in exponential growth

  • Nutrients used up -> insufficient to support further growth
  • Demand for respiratory oxygen increases
  • Enzymes can denature
  • Toxic material can poison/kill
  • CO2 increases -> pH decreases -> enzyme activity decreases
• Primary metabolites


  Substances formed that are essential for microorganism growth, formed in period of active growth eg amino acids, glucose and alcohol
• Secondary metabolites


  Substances formed that are non essential for growth, but still used, formed in stationary phase eg toxins and pigments
• Batch fermentation

  During growth - nutrients are used up, biomass + waste builds up
• Continuous fermentation


  During growth - nutrient medium added continually, culture broth removed
• Controlling bioreactors


  • Temperature - low = slow growth, high = denaturing of enzymes
  • Nutrients + oxygen
  • Mixing
  • Asepsis - contaminants affect yield
  • Sealed units
• Immobilized enzymes


  Enzymes that are bound to an inert, stationary + insoluble material
• Advantages of immobilized enzymesReused

  • more efficient - enzymes present at higher conc than microorganisms
  • more specific - no unwanted enzymes present
  • Greater temperature tolerance
  • less downstream processing - pure product forme
• Disadvantages of immobilized enzymes

  • Lower reaction rate as cannot mix freely
  • Higher initial costs
  • More expensive than free enzymes
  • Higher initial costs of bioreactor system
  • More technical issues
  • Reactors more complex
• Methods of immobilizing enzymes

  • Surface adsorption to ionic carriers -> e.g cellulose, silica
  • Surface covalent binding -> .g carriers with hydroxyl/carboxyl 
  • Entrapment in matrix ->e.g alginate beads
  • Entrapment - encapsulation -> eg within membranes
• Uses of immobilized enzymes

  • Lactase - converts lactose to glucose and galactose
  • Penicillin acylase - converts natural penicillin to semi-synthetic penicillin
  • Glucose isomerase - converts glucose to fructose
  • Glucoamylase - converts starch to glucose syrup
  • Aminoacylase - produces pure L-amino acids