6.2.1 - cloning and biotechnology Flashcards
clones
genetically identical offspring
vegetative propagation
asexual reproduction, which involves taking a part of one plant and producing genetically identical offspring
natural plant cloning - bulbs
e.g daffodil. the leaf bases swell with stored food from photosynthesis and buds form. these develop into new shoots and then new plants
natural plant cloning - runners
e.g strawberries
lateral stem grows away from the parent plant and roots develop where the runner touches the ground. a new plant forms and the runner withers away
rhizomes
e.g marram grass
horizontal stem underground that is swollen with stored food. buds develop and form new vertical shoots that become plants
stem tubers
e.g potato
tip of an underground stem becomes swollen with stored food to form a tuber. buds on the storage organ then develop to produce new shoots
process of cuttings
- take a sample plant you want to clone and cut the under the lateral buds
- place in a rooting hormone, to increase growth
- place in soil and allow to grow with the right conditions
advantages of natural cloning
- quicker than normal reproduction
- identical offspring
- can happen in place of sexual reproduction
disadvantages of natural cloning
lack of genetic variation
susceptible to disease or changing environments
small gene pool
micropropagation
making large numbers of genetically identical offspring from a single parent plant using tissue culture techniques
when is micropropagation used?
when plants
- do not readily produce seeds
- do not respond well to natural cloning
steps of micropropagation
- small sample from meristem is taken
- this sample is sterilised (explant)
- placed in a culture medium containing hormones, stimulating division - causes a callus
- callus divided and transferred onto different culture mediums
- forms plantlets that are potted into compost and left to grow
advantages of micropropagation
allows for large production of plants, making goof yield
disease free plants
streile to meet consumer tastes
provides a wat of growing plants which are naturally infertile or difficult to grow
disadvantages of micropropagation
- genetically identical so all susceptible to same disease
- expensive process, requiring skilled workers
- explants are vulnerable to infection by moulds during production process
example of natural animal cloning
monozygotic twins (identical twins)
- the early embryo splits to form two separate embryos
- when born, they are genetically identical
artificial twinning in cattle steps
- cow with desirable traits fertilised by a bull and early embryos are flushed out of the uterus
- cells are then split to produce several smaller embryos - each capable of growing full term
- grown in the lab and then implanted into surrogate mother
- embryos develop normally into foetuses but are all genetically identical
somatic cell nuclear transfer steps
- nucleus is removed from somatic cell of an adult animal
- nucleus is removed from ovum (enucleated)
- nucleus from somatic cell is placed into the ovum and electrofusion takes place (electric shock to fuse)
- embryo that develops is transfered to uterus of a third animal
- new animal is a clone of the somatic celled animal.
uses of SCNT
- pharming (production of animals that have been genetically engineered to produce pharmaceuticals)
- produce GM animals which grow organs that can be used in human transplants
arguments for animal cloning
- produce more offspring than normal reproduction
- allows for more effective GM
- clone specific animals
- enable rare, endangered, or even extinct animals ti be reproduced
arguments against animal cloning
- inefficient process
- fail to develop
- shortened lifespans
- unsuccessful in increasing rare organism populations
biotechnology
applying biological organisms or enzymes ti the synthesus, breakdown, or transformation of materials in the service of people
why are microorganisms ideal for biotechnology?
- no welfare issues
- range of different microorganims
- genetic engineering
- short life cycle and rapid growth rate
- nutrient requirements are simple and relatively cheap
disadvantages of using microorganisms for biotechnology
need the exact ideal conditions to work effecrively - may produce toxins if the conditions are not maintained.
process has to be sterile
ethical issues with GMOs
how are microorganims used in baking
yeasr - mixed with sugar and water to respire anaerobically - co2 produced makes the bread rise.
how is cheese made using microorganisms
bacteria feed on lactose in milk, changing the texture and tatse, and inhibit the growth of bacteria which make the milk go off.
attempts of using microorganisms to directly produce protein you can eat
Single celled protein
Quorn - others have not been successful
producing penicillin
semi continuous batch process is used - first the fungus grows, then it produces penicillin, then the drug is extracted from the medium and purified.
bioremediation
microorganisms are used to break down pollutants and contaminants in the soil ot in the water
two approaches
using natural organisms - many organisms naturally break down organic material
GM organisms - can break down or accumulate contaminants where they would not normally encounter
lag phase
bacteria are adapting to their new environment - they are growing.
log phase
rate of baterial reproduction is close to or at its theoretical maximum
stationary phase
where total growth rate is 0 - number of new cells formed by binary fission is cancelled out by the number of cells dying
limiting factors affecting growth in a culture of bacteria
- nutrients available
- oxygen levels
- temperature
- build up of waste
- change in pH
primary metabolites
substances that are formed as an essential part of the normal functioning of a microorganism, e.g ethanol
secondary metabolites
substances that are not needed for normal growth, that we can use for our own benefit or processes, e.g penicillin
batch fermentation
- the microorganisms are inoculated into a fixed volume of a medium
- nutrients are used up and waste products build up
- process is stopped before death phase and products are harvested
continuous fermentation
- microorganisms are innoculated into sterile nutrient medium
- added continually
- waste products and desirable products continuiusly removed
how is temperature controlled in a bioreactor?
heating and cool jacket to control temp
thermostat
needs to be at optimum so microorganisms can work effectively
advantages of using isolated enzymes
less wasteful
more efficient - work at much higher concentration
immobilised enzyme
attached to an insoluble material where the substrate passes and is converted to product
advantages of using immobilised enzymes
- can be reused - cheaper
- easily sepaeated from reactants and products they are catalysing
- more reliable
- greater temperature tolerance
disadvantages of using immobilised enzymes
- reduced efficiency - reduce activity rate
- higher initial cost of materials
- bioreactor cost
- more technical issues
entrapment - immobolised enzymes
in matrix, e.g in alginate beads
bonding - immobilising enzymes
covalent bonding with hydroxyl or carboxyl groups
ionic bonds - like cellulose
uses of immobilised enzynes
- immobilised glucose isomerase used to produce fructose from glucose
- imobilised lactase is used to produce lacto fre milk
why are immobilised enzymes more active at certain pHs
less easily denatured as their shape is supported
what is the reason for shaking the milk and the beads in the immobilising enzyme experiment
increased contact area between the enzyme and the substrate - more successful collisions (increased chance of a reaction taking place)
