Cloning And Biotechnology Flashcards
How can we produce natural clones of plants
Vegetative propagation. Part of a plant is separated, then develops into a new plant genetically identical to the original. English Elm does not produce viable seed so it naturally self-propagates using its roots
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 nutrient-containing 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 so makes them more susceptible to disease
Give an example of natural cloning in animals
Monozygotic twins; embryo splits during development to produce two genetically identical twins
How can we produce artificial clones of animals
Somatic cell nuclear transfer; differentiated cell from parent fused with an enucleated egg cell. The cell develops into an embryo and can be implanted into a womb
Embryo splitting; same process by which twins form, performed artificially
Give arguments surrounding cloning in animals
+ Quick process suited to the growing population on earth
+ Can preserve endangered species
- Cloned animals often suffer from health problems
- Low genetic diversity
Why are microorganisms 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, Yoghurt, Cheese
Medicine; penicillin, insulin
Environmental; removing polution
Give advantages of using microorganisms to produce food for human consumption
+ Production rate easily varied
+ Not dependant on climate
+ Long-lasting
+ Uses waste products
Give disadvantages of using microorganisms 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
Aspetic technique; everything must be kept completely sterile so that no unwanted microorganisms are present in the culture
Summarise the three steps of growing microorganisms
- Sterilisation; part of the aseptic technique
- Inoculation; microorganism introduced to agar plate by streaking, seeding or spreading
- Incubation; placed in warm environment for 24-48 hours to grow
Differentiate between batch and continuous fermentation
Batch = closed environment, competition for resources, maintains culture in stationary phase, easy to set up, less efficient
Continuous = 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
Describe the growth curve of a microorganism in a closed culture
Lag = cells increase in size and take in water, population constant
Log = cells divide. Population increases exponentially
Stationary = nutrient levels decrease, slowing growth rate. Population stabilises
Death = toxic metabolites increase to a point that kills cells. Population declines
Give the formula for bacterial growth
N = N0 x 2^n
N - number of bacteria currently 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
- Bonding = enzyme binds with support ionically (adsorption) or covalently
- Entrapment = enzyme placed in a semi-permeable material that allows diffusion of the substrate and product
- Membrane separation = a partially permeable membrane separates enzyme from substrate
Give uses of immobilised enzymes
Glucose to fructose conversion
Semi-synthetic penicillin production
Lactose to glucose / galactose conversion
Pure samples of amino acids
Dextrins to glucose conversion
Evaluate the use of immobilised enzymes
+ Product is not contaminated by ezyme so does not need to be purified
+ Enzymes can be reused
+ Enzymes are protected from harsh environments
- Expensive
- Reaction rate is slower as enzymes cannot move
