22 - Cloning and Biotechnology Flashcards
Which type of reproduction is a type of cloning?
Asexual reproduction
What is cloning?
The production of offspring genetically identical to each other and to the parent
What is vegetative propagation also known as?
Natural cloning in plants
What happens in vegetative propagation?
A structure forms from a part of the parent plant which is genetically identical to the parent
What are 3 parts of a plant which vegetative propagation can occur from?
Leaves, roots, stem
What is vegetative propagation a means of except asexual reproduction?
Surviving from one growing season to the next
What do perennating organs enable a plant to do?
Survive adverse conditions
What are 4 examples of plant parts where natural cloning occurs?
- Rhizomes 2. Bulbs 3. Runners 4. Tubers
What is a rhizome?
A specialised underground stem which is often used as a food store
What is natural cloning used for in horticulture?
Producing new plants
What are 2 advantages of using natural cloning in horticulture?
- Increases plant numbers cheaply 2. Gives many genetically identical plants
What is often applied to cuttings to promote root growth?
Rooting powders
What can be taken from a plant for use in natural cloning?
Cuttings
What are 2 advantages of using cuttings instead of seeds to grow new plants?
- Much faster 2. Guarantees good quality of plants if the parent plant is of good stock
What is the main disadvantage of growing new plants using cuttings?
Lack of genetic variation in offspring can have negative impact if a new disease or pest appears
What are 4 plants commonly grown using cuttings?
- Bananas 2. Cassava 3. Sugar cane 4. Sweet potatoes
What is the most commonly used technique to artificially clone plants?
Micropropagation using tissue culture
What is micropropagation?
The process of making large numbers of genetically identical offspring from a single parent plant using tissue culture techniques
In what 5 situations would micropropagation be used to grow new plants?
“1. When the parent plant doesn’t readily produce seeds 2. When the plant doesn’t respond well to natural cloning 3. When the plant is very rare 4. When the plant has been genetically modified or selectively bred with difficulty 5. When the plant is required to be pathogen-free “
What can scientists in the field use to keep plant tissues sterile during micropropagation?
The sterilising tablets used to sterilise drinking water
What is used to sterilise plant tissue in industrial micropropagation?
Large sterilising units
What is the material removed from the plant in micropropagation called?
The explant
Why is a plant sterilised using water sterilisation tablets more likely to remain sterile?
The chemical doesn’t have to be washed off
What are 2 plant hormones found in the mixture used in micropropagation?
Auxins and cytokinins
What is a callus?
Mass of identical undifferentiated plant cells
Where does micropropagation now take place?
In bioreactors
What are the 6 steps of artificial plant cloning using tissue culture and micropropagation?
- Take small sample from parent plant 2. Sterilise it 3. Place it in sterile culture medium containing plant hormones until a callus forms 4. Divide it up and place in new mixture of hormones and nutrients until plantlets form 5. Pot plantlets until they grow into small plants 6. Plant out small plants to become a crop
What are 3 possible sterilising agents for use in artificial plant cloning?
- Bleach 2. Ethanol 3. Water sterilisation tablets
What are 6 arguments for micropropagation?
- Allows rapid production of good plants 2. Produces disease-free plants 3. Can produce viable amounts of plants after genetic modification of plant cells 4. Can increase numbers of rare plants 5. Can grow plants which are otherwise quite infertile and difficult to grow from seed 6. Can produce very large amounts of seedless, infertile plants to meet customer tastes
What are 5 arguments against micropropagation?
- Produces a monoculture, vulnerable to disease 2. Relatively expensive and needs skilled workers 3. Explants and plantlets vulnerable to infection by pathogens during production 4. If source material infected with virus, all new plants will also have virus 5. Sometimes large numbers of new plants are lost
What type of animals is natural cloning more common in?
Invertebrates
What is an example of how natural cloning can happen in animals?
Starfish can regrow an identical body from a small, detached fragment
What is the main form of vertebrate natural cloning?
Monozygotic (identical) twins
How are monzygotic twins formed?
The early embryo splits to form two identical embryos
Why may monozygotic twins still look different at birth?
Differences in positioning and nutrition in the uterus
Which animals can be relatively easily artificially cloned and how?
Some invertebrates, for example you can just chop off a bit of starfish to grow a new one
What are the 2 main methods of artificial cloning used in animals?
- Artificial twinning 2. Somatic cell nuclear transfer
What commercial sector uses artificial twinning?
Dairy and livestock farming
What is the principle of artificial twinning?
The early embryo is artificially split up to produce 2 or more genetically identical embryos
What do you have to do different when doing artificial twinning in pigs and why?
Implant a number of embryos into the mother pig as they usually have a litter of piglets, so an individual foetus may be rejected or reabsorbed by the mother’s body
What does artificial twinning enable you to increase?
The number of offspring which come from parents with the best genetic characteristics
Why might some embryos be frozen when doing artificial twinning?
You could implant a few unfrozen embryos and assess their success, and if they do well then you can unfreeze and implant the rest
What are the 5 stages of artificial twinning?
- Cow with desirable traits treated with hormones to make her superovulate 2. Fertilise the ova either naturally or via artificial insemination, then gently flush the early embryos from the uterus 3. While the cells are still totipotent, split the embryo into several smaller sections 4. Grow the embryos for a few days, then implant them into surrogate mothers 5. Embryos develop and are born normally
What is superovulation?
Hormonal treatment to increase number of ovulations
What can you do instead of fertilising the ova within a cow in artificial twinning?
Remove the mature eggs from the cow and inseminate them in the lab
Why, in cow artificial twinning, is one embryo implanted per mother?
Because single pregnancies are less risky than multiple pregnancies
What type of animal cloning is used to clone an adult animal?
Somatic cell nuclear transfer
Why are animals of different breeds used as the cell donor, egg donor and surrogate mother in Somatic Cell Nuclear Transfer?
To make it easier to identify the original animal at each stage
What type of cloning was used to produce Dolly the Sheep?
Somatic Cell Nuclear Transfer
What is Somatic Cell Nuclear Transfer also known as and why?
Reproductive cloning, as live animals are the end result
What are the 4 stages of Somatic Cell Nuclear Transfer?
- Nucleus removed from somatic cell of adult 2. Nucleus removed from mature ovum of different female of same species 3. Nucleus from adult animal placed in enucleated ovum and given mild electric shock to stimulate division 4. Embryo transferred to uterus of 3rd animal
What DNA of a clone produced by Somatic Cell Nuclear Transfer does not come from the original animal which had its nucleus taken?
Some mitochondrial DNA comes from the animal which provided the ovum
What are 2 ways in which Somatic Cell Nuclear Transfer is used currently?
- Pharming 2. Producing GM animals to grow organs for human transplant
What are 3 fields in which animal cloning is currently widely used?
- Agriculture 2. Animal breeding 3. Medicine
What are 5 arguments for animal cloning?
- Artificial twinning allows high-yield farm animals to have more offspring 2. SCNT allows specific good animals to be cloned 3. SCNT has potential to aid preservation of rare or even extinct animals 4. Artificial twinning allows the success of a male animal in passing on genes to be determined 5. SCNT enables GM embryos to be replicated and develop
What are 5 arguments against animal cloning?
- Scientists have been increasingly convinced that SCNT will not bring back extinct animals 2. SCNT is a very inefficient process 3. Many cloned animal embryos fail to develop properly and produce deformed offspring 4. Shortened lifespans for many animals 5. SCNT has been fairly unsuccessful so far in increasing the population of rare animals
What is biotechnology?
Applying biological organisms or enzymes to the synthesis, breakdown or transformation of materials in the service of people
What are 5 examples of biotechnology?
- Using yeast to make alcohol 2. Using yeast to make bread 3. Using fungi to make antibiotics 4. Using bacteria to clean up oil spills 5. Enzymes in biological washing powders
What are the 2 main types of organisms used in biotechnology?
- Bacteria 2. Fungi (Yeast)
What are 6 reasons we tend to use microorganisms in biotechnology?
- No welfare issues 2. Enormous range of microorganisms 3. Can be manipulated easily to do reactions which they wouldn’t naturally 4. Microorganisms have very short life cycle and grow rapidly, so lots can be grown 5. Nutrient requirements often simple and cheap 6. Due to simple conditions needed, these too are often cheaper than in non-biological processes
What are 6 disadvantages of using microorganisms in food production?
- Conditions needed for their growth are often very similar to those which microorganisms which make food go off 2. They are often GM, so ethical concerns 3. If conditions aren’t right then the food might not be produced correctly 4. Often need sterile conditions 5. Protein has little flavour so needs additives 6. If large amounts of single-cell proteins are eaten in high quantity, health problems could arise due to high amounts of uric acid when amino acids are broken down.
How does yeast make bread rise?
The yeast aerobically respire and the carbon dioxide thus produced makes the bread rise
How does yeast make alcohol?
Yeast anaerobically respire, using the food provided, and in doing so make ethanol
What 2 compounds are formed by bacteria in yoghurt production?
Ethanol and lactic acid
What effects do bacteria have on the physical properties of yoghurt and how?
Produce extracellular polymers which make yoghurt more smooth and thick
What 2 things do bacteria do in cheese making?
- Feed on lactose in milk, changing the taste and texture 2. Outcompete bacteria which could cause the milk to go off
What is single-cell protein?
Edible protein produced by microorganisms
What is the best-known example of single-cell protein?
Quorn
What fungus is used to make Quorn?
Fusarium venenatum
Is the Fusarium v. fungus itself eaten as Quorn?
No, it produces a protein which is combined with egg white to make Quorn
What is food security?
Having enough food to feed a population, with the population being able to access this food and have a balanced diet
What is used as a food source for Fusarium v.?
Glucose syrup
What 3 types of microorganisms have been used to try to make protein substitutes in the past?
- Fungi 2. Algae 3. Bacteria
What are 2 reasons people argue that more vegetarian diets would increase global food security?
- Vegetables are cheaper, and therefore more accessible 2. A vegetarian diet is more efficient as it involves fewer trophic levels
What are 6 advantages of using microorganisms in human food production?
- Grow and produce protein fast 2. High protein content with little fat 3. Can use a wide variety of waste as food 4. Can be genetically modified 5. Can be made to taste like anything 6. Production is constant on not dependant on weather, breeding cycles etc.
What are 2 examples of medicines produced via biotechnology?
Insulin and penicillin
What type of microorganism is used to produce penicillin?
A mould
What are 4 factors which affect how penicillin is grown commercially?
- Mould is sensitive to pH 2. Mould is sensitive to temperature 3. Mould needs rich nutrient medium 4. Mould needs quite high oxygen levels
What are 5 features of the penicillin production process which optimise the rate of production?
- Buffers in the nutrient medium to keep a constant pH of around 6.5 2. Relatively small fermenters used as it’s hard to keep larger bioreactors sufficiently oxygenated 3. Mixture constantly stirred for oxygenation 4. Rich nutrient medium used 5. Temperature kept constant
What style of manufacturing is used to make penicillin?
Semi-continuous batch maufacturing
What are the 3 stages of penicillin production?
- Fungus grows 2. Penicillin produced 3. Drug extracted from the medium and purified
How was insulin extracted before biotechnology?
Usually from the crushed up pancreases of pigs or cattle slaughtered for meat
What were 4 problems with extracting insulin from the crushed pancreases of dead animals?
- Some were allergic to animal insulin as was often impure 2. Some faith groups forbid pig or cow products 3. Action of animal insulin peaks a few hours after injection 4. Supply erratic and depended on demand for meat (as animal pancreases usually came from stuff slaughtered for meat)
How was the problem of people being allergic to animal insulin eventually alleviated (whilst still using animal insulin)?
Very pure forms were developed which meant that less people reacted badly
What are the 2 approaches to bioremediation?
Using natural and using GM organisms
What happens in bioremediation?
Microorganisms are used to break down pollutants and contaminants in the soil and water
What is an example of GM bacteria being used for bioremediation?
Bacteria which were genetically modified to break down mercury
What are 2 examples of non-GM bacteria being used for bioremediation?
- Usage in cleaning up oil spills 2. Usage in cleaning up sewage and killing the pathogens contained within it
Currently, are GM or non-GM bacteria more successful at bioremediation?
Non-GM, although the gap is narrowing
Where does bioremediation take place?
Often at the site of the contamination, but sometimes stuff is removed to be decontaminated
What is culturing microorganisms?
Growing large quantities
What are 2 reasons health and safety procedures must always be followed when culturing microorganisms?
- Even if they are nominally harmless, mutations are always a possibility and could lead to a microorganism becoming pathogenic 2. There may be contamination from pathogenic microorganisms
What 4 things do microorganisms being cultured need?
- Food 2. The right pH 3. Enough oxygen 4. The right temperature
What is the food which is given to cultured microorganisms called?
Nutrient medium
What are 3 good protein sources which nutrient mediums can be infused with?
- Blood 2. Yeast extract 3. Meat
Do all microorganisms need a precise nutrient balance for their nutrient medium?
No, some do but others just need a good source of protein
What are the 2 forms a culture’s nutrient medium can be in?
- Liquid (broth) 2. Solid (agar)
What is important about the nutrient medium when culturing microorganisms?
That it be kept sterile
What do enriched nutrient media allow?
Samples containing a small number of organisms to multiply rapidly
What are the 4 steps for inoculating broth?
- Make suspension of bacteria to be grown 2. MIx known volume with broth in flask 3. Stopper flask with cotton wool 4. Incubate at suitable temperature, shaking regularly to oxygenate broth
What is inoculating?
Adding bacteria to a nutrient medium
Why is the flask stoppered with cotton wool when inoculating broth?
To prevent contamination from the air
What are the 5 steps for inoculating agar?
- Sterilise inoculating loop by heating until red hot, then make sure it doesn’t touch anything while cooling 2. Dip loop in bacterial suspension 3. Remove lid of agar dish and streak the loop across the surface, taking care it doesn’t dig in 4. Replace lid and loosely hold down with tape 5. Incubate at suitable temperature
What pattern does a bacterial culture’s growth follow?
A standard population growth curve
What are 5 limiting factors which prevent exponential growth of bacteria?
- Nutrient availability 2. Oxygen levels 3. Temperature 4. Waste buildup 5. pH change
What are 6 things any microorganism used in any bioprocess must do?
- Not mutate easily 2. Not produce poison to contaminate the product 3. Work reasonably fast 4. Do the reaction needed 5. Give a good yield of product 6. Use quite cheap nutrients and conditions
What are primary metabolites?
Products necessary for microbial growth
What are secondary metabolites?
They are molecules that are not essential for growth and so in the short term the microorganism would not suffer without them
What are 2 of the main ways of growing microorganisms?
- Batch fermentation 2. Continuous fermentation
What are 2 examples of secondary metabolites?
- Pigments 2. The chemicals which plants produce to protect against herbivory
What are 4 examples of primary metabolites?
- Amino acids 2. Organic acids 3. Alcohol 4. Certain enzymes
What are 4 stages of batch fermentation?
- Microorganisms inoculated into a fixed volume of medium 2. As growth occurs, nutrients used up and waste products and biomass accumulate 3. Culture reaches stationary phase- overall growth ceases, but microorganisms will often carry out biochemical changes to make necessary products 4. Process stopped before death phase and products harvested
What are 3 stages of continuous fermentation?
- Microorganisms inoculated into sterile nutrient medium and start to grow 2. Sterile nutrient medium added continuously to culture once exponential growth reached 3. Culture broth continually removed, keeping culture volume in bioreactor constant
What does continuous culture enable?
Continuous balanced growth
Levels of what 3 things are kept more or less constant in continuous fermentation?
- Nutrients 2. pH 3. Metabolic products
What are most bioreactor systems optimised for?
Maximum production of metabolites
What 2 things can bioreactors be optimised for?
- Maximum production of biomass 2. Maximum production of metabolites
What 2 things is continuous culture used for?
- Some waste water treatment 2. Production of single-celled protein
What type of culture do the majority of industrial processes use?
Batch or semi-continuous
What is used to separate out the useful stuff from in a bioreactor?
Downstream processing
All bioreactors produce a mixture of what 5 things?
- Possibly secondary metabolites 2. Primary metabolites 3. Unused nutrient broth 4. Microorganisms 5. Waste products
What is one of the most difficult parts of the bioprocess?
Downstream processing
What 5 things are controlled within bioreactors?
- Nutrients 2. Asepsis 3. How well the contents are mixed 4. Temperature 5. Oxygen
What are 4 advantages of using isolated enzymes instead of whole organisms?
- Maximised efficiency 2. Less wasteful 3. More specific 4. Purer product, so less downstream processing
What are 4 reasons most isolated enzymes for industrial processes are extracellular?
- They are easier to get and use than intracellular enzymes as they are secreted 2. Tend to be more robust than intracellular 3. Cheaper than intracellular 4. Most microorganisms produce much fewer extracellular than intracellular enzymes, so they are easier to isolate
What are most enzymes used in industrial processes?
Extracellular enzymes produced by microorganisms
Why are isolated intracellular enzymes sometimes still used?
As there are a larger range of them than extracellular enzymes they sometimes provide the perfect enzyme for a particular reaction
What are 3 examples of intracellular enzymes used in industry?
- Asparaginase for cancer treatment 2. Glucose oxidase for food preservation 3. Penicillin acylase for converting natural penicillin into more effective semi-synthetic drugs
When might enzymes be lost in an industrial process?
If they are free rather than immobilised
What is an immobilised enzyme?
One which is attached to inert support structure, over which the substrate passes
Why are immobilised enzymes an example of technology mimicking nature?
In actual cells enzymes are often bound to membranes in a similar fashion
What are 5 advantages of using immobilised enzymes?
- Immobilised enzymes can be reused 2. Enzymes are more easily separated from products and reactants, so less processing 3. More reliable than free enzymes 4. Greater temperature tolerance 5. Greater ease of manipulation
What are 4 disadvantages of using immobilised enzymes?
- Reduced efficiency 2. Higher initial costs of materials 3. Higher initial costs of bioreactor 4. More technical issues
What are 4 ways in which enzymes can be immobilised?
- Surface adsorption to inorganic carriers 2. Covalent or ionic bonding to inorganic carriers 3. Entrapment in a matrix 4. Membrane entrapment in microcapsules or behind a semi-permeable membrane
What are 3 advantages of using surface adsorption to immobilise enzymes?
- Simple and cheap 2. Can be used with a wide variety of processes 3. Enzymes widely available to substrate with virtually unchanged activity
What is a disadvantage of using surface adsorption to immobilise enzymes?
Enzymes can easily be lost from matrix
What are 4 advantages of covalent or ionic bonding to immobilise enzymes?
- Cost varies 2. Enzymes strongly bound so unlikely to be lost 3. Enzymes very accessible to substrate 4. pH and substrate concentration often have very little effect on enzyme activity
What are 2 disadvantages of covalent or ionic bonding to immobilise enzymes?
- Cost varies 2. Active site of enzyme may be modified in process, making it less effective
What is an advantage of using matrix entrapment to immobilise enzymes?
Widely applicable to different processes
What are 4 disadvantages of using matrix entrapment to immobilise enzymes?
- May be expensive 2. Can be difficult to entrap 3. Diffusion of substrate to and from active site can be slow and hold up reaction 4. Effect of entrapment on enzyme activity can be variable
What are 3 advantages of using membrane entrapment to immobilise enzymes?
- Relatively simple 2. Relatively little effect on enzyme activity 3. Widely applicable to different processes
What are 2 disadvantages of using membrane entrapment to immobilise enzymes?
- Relatively expensive 2. Diffusion of substrate to and from active site can be slow and hold up reaction
What are 6 examples of products made from immobilised enzymes?
- Semi-synthetic penicillin 2. Fructose (from glucose) 3. Lactose-free milk 4. L-amino acids 5. Glucose syrup (from starch) 6. Plastics
How are semi-synthetic penicillin made?
Immobilised penicillin acylase used from naturally produced penicillins.
How is fructose made?
Immobilised glucose isomerase to produced fructose from glucose. Fructose is much sweeter (3x)
How is lactose free milk made?
Immobilised lactase is used to split/hydrolyse lactose into glucose and galactose
How to make L-amino acids?
Amnioacylase used to produce pure samples of L-amino acids
How is glucose syrup made?
Glucoseamylase used to break down starch into glucose syrup. Amylase breaks down starch into small polymers called dextrins. The final breakdown of dextrins to glucose is catalysed by immobilised glucoamylase
