CLONING AND BIOTECHNOLOGY 6.2.1 OCR BIOLOGY A LEVEL

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  • Created by: Davina1st
  • Created on: 11-12-21 20:18
What is a clone?
Any cell or individual which is identical to another. Cloning is the process of producing one or more genetically identical individuals. Asexual reproduction by mitosis.
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Describe natural cloning in invertebrates
Regenerate entire animals from fragments of the original if damaged e.g. starfish. Also flatworms and sponges as part of their natural reproductive process.
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Describe natural cloning in vertebrates
Formation of monozygotic (MZ twins) - early embryo splits to form two separate embryos. Although genetically identical, they may look different as a result of their differences in position/nutrition in uterus.
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How is reproductive cloning done? Artificially
Creating a whole new organism genetically identical to another animal, requires use of tori potent stem cells e.g. those found in early embryo, capable of going on to form any cell after differentiation
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What are the two ways in which a reproductive clone can be generated?
Artificial twinning and somatic cell nuclear transfer
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Describe the process of artificial twinning to produce clones in cattle
Early embryo with desirable traits washed out of cows uterus, splits into totipotent cells, each develops into an embryo, transferred to surrogate mothers to produce identical cloned offspring.
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Why is the surrogate mother of artificial twinning treated with hormones?
To make sure the uterus lining is at the correct stage of the female cycle and thick enough to accept embryos for implantation.
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Why are a number of embryos sometimes inserted into each mother, instead of just 1?
If the animal naturally occurs a litter of the babies, the body could reject and reabsorb a single foetus.
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Describe the process of somatic cell nuclear transfer
Nucleus of somatic cell in adult is removed, nucleus of female ovum is also removed, nucleus of somatic cell is placed into enucleated ovum. Given midle electric shock to fuse. Begins to divide and is transferred to surrogate.
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Why is the clone in somatic cell nuclear transfer not 100% genetically identical?
New animal is a clone of the animal from which the somatic cell came from, although mitochondrial DNA comes from the donor egg cell.
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What are three advantages of cloning animals?
Allows high yielding farm animals to produce more offspring than normal, has potential to reproduce rare/extinct animals, embryos for genetic pharming to produce animals capable of producing human products.
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What are three disadvantages of animal cloning?
SCNT is very inefficient takes many eggs to successfully work, many cloned embryos fail to develop properly and end up being miscarried, animals produced by cloning have shorter life spans.
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What is therapeutic cloning?
A method used to regenerate tissues/organs that need repair rather than whole organisms. Stem cells are gathered from embryos from couples who have gone through IVF.
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What are perennating organisms?
Contain stored food from photosynthesis and can remain dormant in the soil, means of asexual reproduction to survive the next season.
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What are four ways in which plants naturally clone themselves?
Bulbs, runners, rhizomes and stem tubers.
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How is a bulb a natural clone?
Leaf bases swell with stored food from photosynthesis, buds form internally which develop into new shoots and new plants the next growing season.
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How are runners natural plant clones?
Lateral stem grows away from the parent plant and roots develop where the runner touches the ground, a new plant develops, the runner eventually withers away leaving the new plant individual.
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How are rhizomes natural plant clones?
Specialised horizontal stem running underground, often swollen with stored food. Buds develop and form new vertical shoots which become individual plants.
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How are stem tubers natural plant clones?
The tip of an underground stem becomes swollen with stored food to form a tuber/storage organ. Buds on the storage organ develop to produce new shoots. e.g. the eyes on a potato.
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How do you clone by taking a cutting?
Cut a stem between 2 leaf joints (nodes), leave 2-3 leaves attached, remove lower ones, cut at an oblique angle=larger SA to help the cutting take up water. Dip the bottom of the stem into a rooting powder. Keep well watered so cutting can support it
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What are advantages of taking a cutting?
Reproducing plants asexually can be isolated and don't need nearby plants like sexual reproduction. Much faster, farmers can generate more plants with useful characteristics and there is guaranteed quality of the crop.
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What are some points to increase the success of taking a cutting?
Use a non-flowering stem, make an oblique cut in the stem, use hormone rooting powder, reduce leaves to 2/4, keep cutting well watered, cover with plastic bag.
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What is micropropagation?
The process of making large numbers of genetically identical offspring from a single parent plant using tissue culture techniques.
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What is the method of micropropagation?
Sample of plant from meristem, make sure plant/conditions are sterilised, explant placed on sterile culture medium-hormones, mitosis stimulated to form undifferentiated mass of cells (callus). Callus subdivided placed on new culture medium=plantlets.
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What are three advantages of micropropagation?
Relatively rapid compared to growth from seed, carried out where sexual reproduction isn't possible (commercially grown bananas), all show the same desired characteristics.
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What are three disadvantages of micropropagation?
Tissue culture=labour intensive, expensive to set up facilities correctly, any contamination = death to all.
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What is biotechnology?
The use of biological organisms to provide a product/service to humans.
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What are three reasons to use microorganisms?
No ethical concerns-no harm/consent, nutritional value increased e.g. kimchi, very short life cycle so can be used quickly.
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What are three advantages of using microorganisms in food production?
High protein content and little fat, no welfare/ethical issues, reproduce fast/produce proteins faster than animals and plants.
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What are three disadvantages of using micro organisms in food production?
Some can produce toxins if optimum conditions are not used, little natural flavour-needs additives, need sterilised conditions that are carefully controlled=trained staff.
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What are the seven biotechnological processes used in food production?
Brewing, baking, cheese making, yoghurt production, penicillin production, insulin production and bioremediation.
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How are micro organisms used in cheese making and yoghurt production?
Cheese-bacteria feed on lactose in milk changing texture and flavour, yoghurt-bacteria produce extracellular proteins that give it a smooth thick texture.
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How are micro organisms used in baking?
yeast respires aerobically - CO2 bubble expand and make the bread rise.
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How are micro organisms used in brewing?
Yeast respires anaerobically to produce to produce ethanol
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How are micro organisms used in penicillin production? Insulin production?
Produced by mould... insulin produced by genetically engineered bacteria.
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How are micro organisms used in bioremediation?
Micro organisms are used to break down pollutants and contaminants in soil and water.
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What is a culture of micro organisms? What is meant by culturing micro organisms?
A population of one type of micro-organisms, growing a population of micro-organisms.
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What are 5 requirements for optimal growth?
Optimum temp, optimum pH, oxygen (unless anaerobic), food-nutrient-liquid(broth)-solid(agar) enriched by yeast/glucose, aseptic conditions-avoiding contamination so culture is pure.
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What are the two ways in which active cultures can be grown?
In suspension (broth) or on an agar plate. Often a master broth culture is made and samples are taken from it to inoculate agar plates for particular experiments/investigations.
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What are the three kinds of agar plate?
Spread-making a lawn of pure culture for testing antibiotics/antiseptics, pour-serial dilutions, streak-isolating a single micro organism from a mixed colony.
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What are aseptic techniques? give an example
Ways to reduce contamination from other bacteria/fungi in an experiment. Putting the mouth of a bottle through a Bunsen flame.
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How is a broth inoculated?
Make a suspension of bacteria to be grown, mix know volume with sterile nutrient broth in flask, stopper flask with cotton wool to prevent contamination, incubate at suitable temp shaking regularly for O2.
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What are three advantages of human microorganisms to produce human food?
Reproduce faster and produce protein faster than animals and plants. High protein content and little fat. Microorganisms can use a wide variety of waste materials including human and animal waste, reducing costs.
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What are three disadvantages of using microorganisms to produce human food?
Some microorganisms can also produce toxins if conditions are not kept optimum. Need sterile conditions that are carefully controlled adding to costs, often GM which people have concerns about eating.
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How do you inoculate agar?
Wire inoculating loop sterilised by bunsen burner (red hot), dip loop in bacterial suspension and make zigzag streak across the surface of agar, surface of agar kept intact. Replace the lid of petri dish, held down with tape but oxygen can still get
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What are the 4 stages of the bacterial growth curve? Describe what happens at each
Lag phase-adapting to new environment, log/exponential-rate of reproduction at theoretical max, stationary phase-number of new cells=number of dying cels, decline/death-reproduction ceased and death rate increase.
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What are some limiting factors which prevent exponential growth in a culture of bacteria?
Nutrients availability, oxygen levels, temperature, build up of waste, change in pH
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What is a a metabolite?
Substances produced by the metabolism (chemistry) going on in an organism. May be useful chemicals or waste e.g. hormones or CO2
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What is a primary metabolite?
A substance produced as an essential part of the normal functioning of the organism. e.g. alcohol by yeast as a product of aerobic respiration.
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What is a secondary metabolite?
Substances only produced by an organism in the stationary phase (response to competition)
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What is the difference between batch fermentation and a continuous culture?
Batch is closed, nothing is added or taken away until complete. whereas an open culture has nutrients replenished and waste removed.
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Describe a bioreactor
Temperature sensors probes/sample tests to monitor O2, stirred continuously to make sure all organisms receive food and oxygen, simple diffusion is not enough. Sealed and aseptic.
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How are aseptic conditions established and maintained in a bioreactor? (4)
Heat to sterilise (steam or hot water), vessels kept in a sterile environment, all staff wear PPE. Air is filtered and extraction fans present. Waste products removed/filtered through outlets.
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What are some advantages of using isolated enzymes instead of the whole organism?
Less wasteful, more efficient, more specific, maximise efficiency.
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What are some advantages of using immobilised enzymes?
Can be reused=cheaper, more reliable, high degree of control, greater temperature tolerance=less expensive cost to run bioreactor.
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What are some disadvantages of using immobilised enzymes?
Reduced efficiency, process of immobilisation might reduce its activity rate, Higher intial cost of materials, more expensive to produce than free enzymes, but do not need to be replaced as frequently. More technical issues.
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What is an immobilised enzyme?
An enzyme attached to an inert, insoluble material e.g. calcium alginate.
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How is surface immobilisation carried out? advantages and disadvantages.
Adsorption to inorganic carriers, e.g. cellulose/carbon nanotubes. Simple and cheap, used in many different processes. Enzymes lost from matrix relatively easily.
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What are the advantages/disadvantages of surface immobilisation by covalent/ionic bonding?
Cost varies, enzymes strongly bound and unlikely to be lost, enzymes accessible to substrate. Active site may be slightly modified in process making them less efficient.
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What are the advantages/disadvantages of immobilisation by entrapment (in matrix)?
Widely applicable to different processes, may be expensive, can be difficult to entrap, diffusion of substrate to and from active site can slow down reaction time.
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What are some uses of immobilised enzymes in real life?
Immobilised lactase to produce lactose free milk. Immobilised penicillin acylase to make synthetic penicillin=able to kill bacteria that penicillin doesn't. immobilised aminoacylase to produce pure samples of amino acids for use in pharmaceuticals.
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Card 2

Front

Describe natural cloning in invertebrates

Back

Regenerate entire animals from fragments of the original if damaged e.g. starfish. Also flatworms and sponges as part of their natural reproductive process.

Card 3

Front

Describe natural cloning in vertebrates

Back

Preview of the front of card 3

Card 4

Front

How is reproductive cloning done? Artificially

Back

Preview of the front of card 4

Card 5

Front

What are the two ways in which a reproductive clone can be generated?

Back

Preview of the front of card 5
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