6.2.1- Cloning and Biotechnology Flashcards
what is cloning?
A method of producing genetically identical offspring by asexual reproduction.
what are clones?
genetically identical copies of genes, cells or organisms
what is reproductive cloning?
the production of genetically identical individuals
how do prokaryotes clone themselves naturally?
by binary fission (cells split in two)
how do eukaryotes clone themselves naturally?
by asexual reproduction (divide by mitosis)
what is asexual reproduction known as in plants?
vegetative propagation
how do plants clone themselves naturally?
by growing new plants from growing points (meristem), which contain undifferentiated stem cells that are capable of dividing and differentiating to produce new individual plants called cuttings
what are the three advantages of using asexual reproduction for natural cloning?
1- Rapid colonisation (saves time finding mate and producing gametes)
2- Allows reproduction in absence of mates
3-All offspring are well-adapted to current environment
what is the disadvantage of using asexual reproduction for natural cloning?
no genetic variation/diversity
what is vegetative propagation?
any form of asexual reproduction that occurs in plants, where a new plant grows from a fragment of the parent plant or specialised reproductive structure
what are four examples of vegetative propagation?
-bulbs, daffodil= the leaf bases swell with stored food for photosynthesis
-runners, strawberries= lateral stem grows from the parent plant, roots develop when it touches the ground
-rhizomes, marram grass=horizontal stem running underground, swollen with stored food
-stem tubers, potato= tip of underground stem becomes swollen into stored food and forms a tuber, the buds on the tuber develop to produce new shoots
what are the 3 techniques of horticulture and explain these?
1= cuttings, cut stem treated with plant hormones
2= grafting, cut stem inserted into groove on a different plant stem
3= splitting bulbs, splitting up bulbs or cutting up rhizomes.
what are some advantages of using cuttings to crop plants rather than using seeds?
-all plants will be the same (height, size, flowering, etc) to the stock plant
-guarantees quality
-much faster time from planting to cropping
what are some disadvantages of using cuttings to crop plants
-decreases genetic diversity
-if one plant is effected by disease, they all will be
why should cuttings be taken at an angle?
-greater surface area
-increased water uptake
-enhances survival
is horticulture natural or artificial cloning?
artificial
how does vegetative propagation occur in elm trees?
-elm tree roots contain meristem tissue which divides by mitosis to produce root suckers, which do not usually survive in crowded woodland due to competition for sunlight
-if the main trunk is destroyed during disease, burning or felling, a ring of root suckers starts to grow called a clonal patch
what is the disadvantage of vegetative propagation in elms?
suckers are just as susceptible to diseases as the original tree, as they are genetically identical
what is the main advantages of vegetative propagation in elms?
-survive burning and felling
-recolonise rapidly
what are the 6 steps to taking plant cuttings used in horticulture?
1-use a non-flowering stem
2-make an oblique cut with a sharp scalpel
3-use a hormone rooting powder
4-reduce leaves
5-keep cutting well watered
6- cover the cuttings with a plastic bag
explain the steps in taking plant cuttings used in horticulture?
1-so resources are used to grow the roots
2-large sa, sharp to prevent cell damage
3-synthetic auxins, to allow adventitious roots to grow
4- less stress on plant so increases survival
5- has no roots to absorb water, ensures survival
6-humidity, stops plant drying out and reduces water loss
what is another example of artificial cloning in plants?
micropropagation/tissue culture
what is micropropagation/tissue culture?
the process of making large numbers of genetically identical offspring from a single parent plant using tissue culture techniques.
when is tissue culture used?
-plants that do not readily produce seeds
-plants that do not respond well to natural cloning
-rare plants
-plants that have been genetically modified or selectively bred with difficulty
-plants required to be ‘pathogen free’
what are the 6 steps to micropropagation/tissue culture?
1- explant cells are removed from the meristem of the shoot tip of the plant to be cloned
2- explant cells are sterilised and placed on a sterile nutrient agar containing a balance of cytokinin and auxin to stimulate mitosis
3- they grow into a ball of undifferentiated cells called a callus
4- callus is subdivided and grown on sterile nutrient agar containing auxins
5- these hormones stimulate differentiation to produce thousands of miniature plants
6- miniature plants are called plantlets which are transferred to soil to grow bigger
what are some pros of using tissue culture?
-small amount of tissue used to mass produce
-independent of season growth
-disease-free crops
-uniform crops with desired characteristics
-it can be used for conservation of rare species
what are some cons of tissue culture?
-expensive
-sterile conditions needed
-explants and plantlets are vulnerable to moulds
-labour-intensive, trained staff
what are the two methods of producing genetically identical animal clones?
1= splitting embryos
2= somatic cell nuclear transfer
what occurs during artificial twinning /splitting embryos?
-animal embryos contain totipotent stem cells
-split embryos are implanted into surrogate mothers
-each one grows into a genetically identical animal, equivalent to identical twins
explain somatic cell nuclear transfer?
-nucleus removed from differentiated cell of donor adult
- nucleus is placed into an enucleated egg cell
-newly created cell is implanted into surrogate mother
-this develops into a new individual, which is genetically identical to the donor adult
what is an example of somatic cell nuclear transfer?
dolly the sheep
what are the positive of animal cloning?
-high production
-important for pharming
-replaces specific pets, clone top class racehorses
-preservation of rare/endangered species
-potential to reproduce extinct animals
what are the concerns of artificial cloning in animals?
-animal welfare
-reduced lifespan and unknown health risks
-many failed embryos
-genetic uniformity so entire herd could be wiped out by the same disease.
what is therapeutic cloning/non-reproductive cloning?
the production of genetically identical cells, tissues and organs to replace those damaged by accidents/disease.
what is the potential uses of therapeutic cloning?
-regeneration of heart muscle after a heart attack
-repair to nerve tissue damaged by multiple sclerosis
what is biotechnology?
the industrial use of living organisms or parts of living organisms, to produce food, drugs or other products.
why are microorganisms ideal for biotechnology?
-short life cycle so they grow rapidly
-produce proteins/chemicals, that can be easily harvested
-genetically engineered to produce specific products
-grow well at low temperatures, so economical to use
-grown anywhere
-more pure
-no welfare issues.
what foods/drinks are microorganism and biotechnology used to make?
-bread
-beer
-cheese
-yoghurt
what are the steps in making bread through biotechnology?
-active yeast mixture is added to flour/other ingredients, mixed and left to rise in a warm environment
-dough is knocked back (excess air is removed), kneaded and shaped
-it is then cooked in a hot oven, so the CO2 bubbles will expand, yeast cells are killed and bread will rise
what are the steps to brewing beer in biotechnology?
-
what are the steps to cheese-making in biotechnology?
-yeast cells are genetically modified to produce the enzyme chymosin, which clots the milk
-lactobacillus also converts the lactose in the milk into lactic acid, which make it turn into a solid curd and liquid whey
-fungi is added to give flavour and colour
what are the steps to yoghurt production in biotechnology?
-lactobacillus clots the milk and causes it to thicken
what is the production of bread, beer, cheese and yoghurt an example of in terms of food production?
indirect food production
what is an example of direct food production?
single-cell protein, Quorn
how is quorn made?
made from the fungus Fusarium venetatum that is grown in large fermenters using glucose syrup as a food source
what are the 7 advantages of using microorganisms to produce human food?
-reproduce fast
-high protein content with little fat
-variety of waste materials used, reducing costs
-genetically modified to produce protein required
-not dependent on weather, breeding cycles
-no welfare issues when growing microorganisms
-can be made to taste like anything
what are the 7 disadvantages of using microorganisms to produce human food?
-produces toxins if conditions are not maintained
-have to be separated from broth and processed to make food
-involve GM organisms, concerns
-protein has to be purified to ensure it contains no toxin/contaminants
-people dislike thought of eating microorganisms grown on waste
-has little natural flavour, needs additives
what is penicillin?
the first commercial product of the antibiotic produced by mould
what was the mould that produced penicillin called?
Peniciilium chrysogenum
what does P.chrysogenum need to grow and what needs to be controlled?
-to grow= high oxygen levels, rich nutrient medium
-controlled= pH and tempterature
what is bioremediation?
the use of organisms to remove toxic materials from the environment?
what is bioremediation used for?
to remove pollutants like sewage and crude oil by breaking them down into less harmful products
what is an example of where bioremediation was used?
during the Deepwater Horizon spill in 2010, which was disastrous for the environment?
what is culturing microorganisms?
to investigate microorganisms for medical diagnosis or disease or for scientific experiments, you need to culture them, which involves growing large enough numbers so we can see them clearly
what is essential during culturing microorganisms?
-right conditions of temperature, oxygen and pH
-need food provided for the nutrient medium, this can be either broth or agar
what is asepsis in the absence of unwanted organisms?
techniques used to avoid contamination of cultures, and the precautions taken to ensure the unwanted microorganisms do not contaminate cultures of microorganisms or products.
what 4 ways do contaminants reduce product yield?
-compete for nutrients and space
-may cause spoilage of product
-may produce toxic chemicals
-may destroy unwanted microorganisms
what 3 things do aseptic techniques help to exclude contaminants from?
-nutrient media (nutrient sources that microorganisms are grown on)
-culture vessels (containers microorganisms are grown in)
-implements used to transfer microorganisms
what should the medium during asepsis contain?
-energy source
-carbon source
-nitrogen source
-mineral salts
-growth factors
-water
how do you inoculate broth?
-mix the suspension of bacteria to be grown with sterile nutrient broth in the flask.
-cotton wool is usually used as a stopper to prevent contamination
-incubated at a suitable temp, and shook regularly to provide oxygen
what are 5 aseptic techniques?
-flaming
-irradiation
-autoclave
-laminar flow cabinet
-keep cultures closed
explain the flaming technique?
use a bunsen burner to heat metal loops until glowing for transferring microorganisms
explain the irradiation technique?
use UV and gamma rays to irradiate plastic containers used in culturing
explain the autoclave technique?
use steam-sterilisation to prepare nutrient media and glass vessels
explain the laminar flow cabinet technique?
-handle microorganisms in a laminar flow cabinet, where air circulation carries airborne contaminants away from the bench space
-alternatively swab with disinfectant before and after use, and work near a bunsen flame to create an updraft
explain the keep cultures closed technique?
if opened, hold petri dish ajar, flame bottle becks and do not place lids on benches
what does the growth curve show?
shows the population size over time for a closed culture
what are the 4 distinct stages of the growth curve?
1- lag phase
2- exponential phase
3- stationary phase
4- death phase
what happens in the lag phase of the growth curve?
-organisms adjust to surroundings
-cells active but not reproducing
-taking in water, cell expansion, activating genes, making enzymes
what occurs in the exponential phase of the growth curve?
-population size doubles each generation as every individual has enough space and nutrients to reproduce
-cells reproducing exponentially
what occurs in the stationary phase of the growth curve?
-waste products build up
-oxygen, nutrients and space run out
-rate of cell production = rate of cell death
-cells reproducing at same rate at which they are dying
what occurs in the death phase of the growth curve?
-nutrient exhaustion
-increased levels of toxic waste products and metabolites lead to increased death rate
-death rate increases above reproductive rate
what are the 3 techniques used to measure population growth?
1- direct counting
2- viable counting
3- turbidimetry using a colorimeter
what is the equation used for viable counting?
number of bacteria/ml= number of colonies x dilution factor
what microorganisms does direct counting give the total count for?
both dead and living
what microorganisms/cells does viable counting count?
only live cells
when is viable counting beneficial?
when an agar plate is inoculated a solid mass of microbial growth is present and you are unable to count the individual colonies
what is involved in turbidimetry using a colorimeter?
samples are placed into a colorimeter, and a reading is taken
-must calibrate the turbidity readings by comparing them against the total counts/viable counts
what does a colorimeter measure?
the absorbance of particular wavelengths of light by specific solution
why is it important to calibrate the colorimeter?
to ensure that a constant reading is done that represent changes in experiment not instrument, container or buffer used
what type of cells are used in turbidimetry?
dead and living cells
what are primary metabolites?
substances produced by an organism as part of it’s normal growth
what are secondary metabolites?
substances produced by an organism that are not part of it’s normal growth
compare the concentration of primary metabolite and secondary metabolite to the growth curve?
primary= matches the growth curve
secondary= rises throughout stationary stage
what happens to production in primary and secondary metabolites?
primary= production starts during lag phase (continues throughout), with rate of production being fastest in exponential phase
secondary= production starts at end of exponential, with rate being fastest during stationary phase
how is insulin created using bioremediation?
genetic engineered bacteria has allowed for the production of human insulin to treat type 1 diabetes
= bacteria is grown in fermenters and downstream processing results in a constant supply
what are industrial scale fermenters?
huge tanks that can hold up to 100,000 dm^3 of culture broth
how are microorganisms transferred to the industrial scale fermenter?
using scale-up to inoculate
= moos are transferred from an agar plate to a small fermenter that are then transferred to a bigger fermenter, and so on so that te huge fermenter is inoculated with a large ‘starter’ population
what are the 4 growing conditions that ensure a high product yield?
-temperature
-pH
-oxygen (needed for aerobic respiration)
-type and time of nutrient addition
what are the two types of cultures produced through industrial scale fermentation?
1= batch culture
2= continuous
explain batch culture?
-moos grown in a fixed volume of nutrient medium for a fixed period of time
-produce is removed at the end
-only oxygen added and only carbon dioxide removed
-go through lag, exponential and stationary
-grow until conditions become unfavourable
-used for obtaining secondary metabolites
explain continuous culture?
-nutrients added to tank and products removed continuously
-fresh sterile medium added, cells/spent medium removed at same rate
-kept in exponential phase
-grow indefinitely
-used for obtaining metabolites
what are the pros and cons to batch culture?
-growth rate is slower
-easy to set up and maintain
-only one batch is lost if contamination occurs
-less efficient, as fermentation tank is emptied
-very useful for processes involving production of secondary metabolites
what are the pros and cons of continuous culture?
-growth rate is higher as nutrients constantly added
-more complicated to set up and maintain
-if contamination occurs huge volumes of product will be lost
-more efficient
-useful for processes involving production of primary metabolites
what are immobilised enzymes?
enzymes that are attached to or trapped in a solid support so they can be used over and over again.
what problem does using immobilised enzymes overcome?
gets over the problem that enzymes are expensive to produce and to separate them from a reaction mixture
what are the 3 advantages of immobilised enzymes?
-they can be used over and over again because they remain attached in a solid support
-enzymes should not contaminate product, but they could leak
-enzymes are more stable
what are the disadvantages to using immobilised enzymes?
-reduced activity
-expensive to set up initially
-contamination is costly to deal with
what are the 4 different ways of immobilising enzymes?
1= absorption
2= covalent bonding
3= entrapment
4= membrane separation
what are biosensors used for?
used to accurately monitor the blood and urine levels of substance, with the immobilised enzymes reacting with a specific substrate and the chemicals produced are detected by the sensors
