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72 Cards in this Set
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- Back
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What is cloning? Advantage Disadvantage |
Producing genetically identical organisms Advantage = only one parent needed, number of endangered species increase , genetically identical offspring have favourable allele Disadvantage = no generic diversity so unable to adapt to environment, no natural selection |
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What is vegetative propagation? |
Asexual reproduction in plants and occur in flowering plants and involve perennating organs |
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What is perennating organs ? Examples |
Store enough nutrient for organism during unfavourable seasons and develop into new plants Bulb, runner, rhizome, stem tubers and suckering |
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What is a bulb in plants ? |
Base of leaf swell due to stored food, bud form internally and form new shoots into new plant |
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What is runners in plant? |
Stem grows laterally away from parent and roots develop where runner touch ground and new plant form |
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What are rhizome in plant? |
Stem grows laterally underground and swollen with food, buds develop and form new vertical shoots to become new plant |
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What are stem tubers? |
Top of underground stems become swollen with stored food to form tuber, buds develop to produce new shoots |
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What do farmers do to increase rate of new plants? |
Spilt bulbs, remove young plants from runners, take cuttings |
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What is taking cuttings ? |
Short section of stem cut at a slant between nodes and planted |
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Steps of taking a cutting |
Use a non flowering stem so energy is not wasted Reduce leaves to three to reduce water lost by transpiration Make oblique cut in stem to increase surface area for uptake of water Use auxins for development of roots Cover cutting with plastics bag for few days to reduce transpiration Keep well watered for photosynthesis |
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Advantage of vegetative propagation |
Quicker than growing from seed Some crop plants cannot reproduce sexually Young seedlings are less likely to survive Uniform quality size and yield so easy to harvest Can be done any time of the year |
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What is the benefit of plants being totipotent? |
Able to produce large quantities of identical clones from one desirable plant |
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What is micropropagation? |
Create genetically identical plants grown from small pieces of plant tissue on sterile nutrient rich jelly |
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Why carry out micropropagation? |
Plants cannot naturally clone Does not produce seed Rare so want to increase number Has been genetically modified or selectively breed with difficulty Required to be pathogen free |
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Micropropagation steps |
Group of cells removed from parent plant called explant Explant is sterilised in bleach, ethanol or sodium dichloroisocyanurate Explant is placed on nutrient rich medium containing auxins, gibberellins and cytokinins to stimulate mitosis Cells divide to form mass of undifferentiated cells called callus Single cells removed from callus and placed on growth medium with different proportion of hormones to stimulate root growth Each develop into a plantlet |
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What is the advantage of micropropagation? |
Raid production of large number of plants with known genetic make up Produce viable number of genetically modified plants Culturing meristem tissue produce disease free plants Produce large numbers of plant which is seed less so sterile to customers Increasing number of endangered and relatively infertile plant |
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Disadvantage of micropropagation |
Produce monoculture so all susceptible to diseases and environmental changes Expensive and required skill worked Explants vulnerable to infection Source is infected with virus all clones will be infected |
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Examples of natural cloning in invertebrates |
Flatworms and sponges fragment to form new identical animals Hydra produce small buds on side develop into. Likes |
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Natural cloning in vertebrates |
Monozygotic twin - early embryo split to form 2 separate embryos |
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What is artificial twinning? Uses |
1 sperm fertilise 1 embryo which divides into ball of cells Embryo have identical totipotent cells and manually split into smaller embryos Used by farmers to produce maximum offspring from one good animal |
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Process of artificial twining |
Cow with desirable traits treated with FSH hormone so they super ovulate and produce more mature ova Ova Fertilise naturally or by artificial insemination by sperm from bull with good traits mature ova remove from fallopian tube and fertilise in vitro Early embryos are flushed out of uterus and screen for sex and genetic defects Around day 6, totipotent embryo cells are split into smaller embryos Each embryo grown in lab for few days to ensure all is well Each implanted into surrogate mother and cows are treated with oestrogen and progesterone to thicken and vascularise uterus lining for implantation of embryo Embryo develop into foetus and born naturally to get number of identical clones |
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What is somatic cell nuclear transfer? Uses |
Somatic cell nucleus is transferred into enucleated egg cell so it divides Increase endangered species, in farming to increase animal with desirable traits |
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Process of somatic cell nuclear transfer |
Somatic cell removed from donor adult and nucleus is removed Unfertilised egg cell removed from female of same species and nucleus is removed Using practical procedures such as electric pulse or micropipette, somatic cell nucleus is placed into enucleated egg ( electro fusion- placed next to each other and two cells fused under electric current ) Cells divide into embryo and implanted into surrogate mother Surrogate mother gives birth and new animal is genetically identical to animal that donated somatic cell |
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Why is new organism produced from somatic cell transfer nucleus not perfectly genetically identical to donor parent? |
Egg cell contain mitochondrial DNA passed onto offspring Spontaneous mutation |
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Arguments for animal cloning |
AT allow high yielding farm animals with desirable genes SCNT allow GM embryo to be replicated and develop so only one engineering procedure and important in pharming Potential to increase endangered animals or extinct animals to be reproduce |
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Arguments against animal cloning |
Many cloned embryo fail to develop, miscarry or produce malformed offspring Have shorter lifespan SCNT is inefficient as takes many eggs to produce single cloned offspring Relatively unsuccessful so far increasing endangered species or bring back extinct animals |
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Why microbes are used for biotechnology? |
Fast reproduction rate and short life span so large quantities made in short time No welfare considerations as no nervous system so only optimal conditions needed Asexual reproduction so population are genetically identical Genetic modification is easier due to bacteria only having one chromosome Cheap nutrient requirement as bacteria can be gm to use wast material Microbe produce own catalyst so lower temperature so cheaper |
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Direct food production Process |
Production of single cell protein using microbes Microbe grown in large fermenter using glucose syrup Microbe combine with albumin and mixture is compressed to from meat substitute |
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Advantage of single cell protein using microbes |
High protein content with little fat Produce protein faster than animals and plants Use wide variety of waste material do reduce cost Breeding cycle can match demand No welfare issue |
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DisAdvantage of single cell protein using microbes |
If conditions not ideal some microbes produce toxins Microbe have to be separated nutrient broth and processed to make food Sterile conditions carefully controlled so add to cost Protein needs to be purified so no contaminants Need additives |
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Penicillium grow on Spores are |
Bread and fruits Widespread so can easily contaminate culture dishes |
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Conditions for producing penicillin |
High oxygen level and rich nutrient medium Sensitive to pH and temperature Semi continuous batch |
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Why insulin from GM bacteria is better than pig insulin? |
Supply of pig insulin is not regular and depended on demand of meat Some people allergic to animal insulin Some faith groups not permitted to use pig products Peak activity of animal insulin is several hours after injection so hard to calculate when to eat meals Bacteria grown in fermenter so provide constant supply |
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Bioremediation Natural example GM example |
Organism used to break down contaminants and pollutants in soil and water Bacteria break down waste and oil spill Being developed to remove mercury from water |
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Culturing meaning |
Growing large enough quantities of bacteria do they are visible to naked eye |
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Risk of growing microbes |
Mutation can make the microbe a pathogen Contamination with pathogen from environment |
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Bacteria is added to nutrient broth or agar by |
Inoculation |
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Inoculating broth process |
Sterilise wire loop in Bunsen flame until glows red hot and let cool Dip sterilised loop in sample from pre grown agar plate Sample mix in known volume of sterile nutrient broth Place cotton wool or lid over flask to prevent contamination Incubate at suitable temperature and shake regularly to provide oxygen |
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Inoculate agar process |
Sterilise wire loop in Bunsen flame until glows red hot and let cool Dip sterilised loop in sample from pre grown agar plate Remove Petri dish lid of sterile plate and make zig zag across surface Replace lid and hold down with tape but do not seal completely to prevent growth of anerobic bacteria Incubate at suitable temperature with agar side up |
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Why do a zig zag streak on agar plate? |
See growth of single colonies to identify species of bacteria more easily and estimate number of bacteria in original sample as single colony grown from single bacteria |
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How to maintain aseptic technique? |
Work in inoculating cabinet Minimum plate opening time Seal plate for incubation Flame inoculating loop |
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Indirect food production example Disadvantage |
Cheese making, bread, yoghurt Non ideal conditions hinder growth Ideal conditions are also ideal for un wanted microbes causing food contamination Sone people don’t like gm microbes for food |
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Lag phase |
Bacteria acclimatising to new conditions so take a while for enzyme production so not replicating at maximum |
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Log phase |
Number of bacteria increasing rapidly and replicating rate is close to theoretical max, little intraspecific competition |
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Stationary phase |
Rate of replication by binary fission is rate of death so growth rate is 0 and carrying capacity is reached |
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Decline phase |
Replication almost ceased and death rate increases and toxic material build up |
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Limiting factors for growth of bacteria |
Oxygen level pH Temperature Nutrients Waste level |
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How to estimate number of bacterial cells in a sample |
Serial dilution and plate them on agar |
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Bioprocess What does a good bio process mean ? |
Microbe Synthesising or breaking down chemical compounds Produce high yield, fast, use cheap material, no extreme conditions required, no toxins produced |
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Metabolism meaning Metabolites meaninh |
Chemical reactions which produce new cell, cell components , chemicals and waste products Substances produced during cell process |
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Primary metabolites Example |
Substance produced by organism as part of normal growth and matches growth in population Amino acid, enzyme |
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Secondary metabolites Example |
Substance produced not essential for growth and formed after growth phase and during stationary phase Antibiotic, pigment |
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Conditions to controlled in a bioreactor |
Temperature Nutrients Oxygen pH Aseptic conditions |
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What is immobilising isolated enzymes? |
Enzymes attached to inert support system which means enzymes are hold stationary and substrate passes thru it and convert to product |
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Advantage of immobilising enzymes |
Held stationary so can be reused so cheaper Easily separated from reactants and products so less downstream processing so cheaper More reliable and provide high degree of control as insoluble support provide stable micro environment Greater tolerance to temperature and pH so less easily denatured Can be used continuously by continuous flow of substrate in |
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Disadvantage of immobilising enzymes |
Reduce efficiency as it could reduce activity rate Higher initial cost of enzymes Higher initial cost of bioreactor More technical issues |
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4 ways of immobilising enzymes |
Surface immobilisation Adsorption Encapsulation Lattice entrapment |
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What is surface immobilisation? |
Amino groups of enzymes are cross linked using glutaraldehyde |
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What is adsorption? |
Enzyme attached to inorganic carrier or inert surface such as cellulose silica and glass beads |
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What is encapsulation? |
Enzyme trapped in a gel bead Disadvantage is that reaction rate is reduced as need to get through trapping barrier |
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What is lattice entrapment ? |
Enzyme separated from mixture by partially permeable membrane |
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How is oxygen controlled in a bioreactor ? |
Bubble through broth and paddles used to spread through broth |
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How is pH is controlled in bioreactor? |
Buffers added |
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How is aseptic condition controlled ? |
Fermenter, medium and gas sterilise pasteurised steam or chemical Maintain pressure difference between air in room and outside so steady flow of air out of room Ensure culture of microbe is pure |
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Batch fermentations process |
Microbe inoculated with specific quantity of nutrient at start Allow to grow for fixed period until nutrient used up and biomass accumulate As culture reaches stationary phase, overall growth stop and microbes produces secondary metabolites Process is stopped before death phase and products are harvested |
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Continuous culture process |
Microbes inoculated into sterile nutrient medium and start to grow Sterile nutrient medium added continuously to culture to remain at exponential phase Culture broth continually removed to keep volume constant |
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Calculate population of culture |
Nt = N0 * 2^n Nt = number of cells at time t N0 = initial number of cells n = number of generations in time t |
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What are isolated enzymes and the advantage of using isolated enzyme ? |
Enzyme separated from microbe Less wasteful as whole organism could use up substrate for biomass More efficient as works at higher concentration than when they inside organism More specific as no unwanted enzyme present Less downstream processing so product is pure |
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Advantage of using extra cellular enzyme for industrial processes? |
Easy to isolate Easy to identify as microbes produce few extra cellular enzymes More robust as designed to withstand uncontrolled environment outside cell |
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Advantage and Disadvantage of using intracellular enzymes for industry |
Bigger range so more ideal for some processes More expensive to extract |
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Method for immobilising enzyme with encapsulation |
Enzyme solution mixed with sodium alginate solution Droplets of solution added to calcium chloride Droplet turn into bead |
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What does the motor in fermenter do ? What does cooling water inlet do? What does paddle do? |
Back (Definition) |
