6.2 Cloning and Biotechnology Flashcards
What is cloning?
the process of producing genetically identical cells or organisms from existing cells or organisms
Natural Cloning
what is vegetative propagation?
the production of plant clones from non-reproductive tissues e.g roots, leaves and stems
what are rhizomes?
- stem structures that grow horizontally underground away from the parent plant.
- they have nodes from which new shoots and roots can develop
what are runners?
- stem structures that grow above ground on the surface of the soil.
- new shoots and roots can either develop from nodes or form at the end of the runners
what are suckers?
- shoots that grow from sucker buds (undeveloped shoots) present on the shallow roots of a parent plant.
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what are tubers?
- large underground plant structures that act as a food store for the plant
- they’re covered in ‘eyes’.
- each eye is able to sprout and form a new plant
what are bulbs?
- underground food stores used by plants, such as onion plants.
- new bulbs are able to develop from the original bulb and form new individual plants
How do you produce a clone from cuttings?
1) Use a scalpel to take a cutting from the end of a stem of your parent plant.
2) Remove the leaves from the lower end of the cutting, leaving just one at the tip.
3) Dip the cut end of the stem in rooting powder, which contains hormones to induce root formation.
4) Then, place the cutting in a suitable growth medium, such as well-drained compost.
5) Provide the cutting with a warm and moist environment.
6) When the cutting has formed its own roots and is strong enough, you can plant it elsewhere to continue growing.
What are the methods of natural cloning?
- Vegetative propagation
- Cuttings
what is micropropagation?
the process of taking a small piece of plant tissue and using plant growth substances to encourage it to grow and develop into a whole new plant
How are artificial plant clones produced?
using tissue culture
Describe the process of tissue culturing
1) Cells are taken from the original plant that’s going to be cloned.
2) Cells from the stem and root tip are used because theyre stem cells.
3) The Cells are sterilised to kill any microorganisms.
4) The Cells are placed in a culture medium containing plant nutrients and growth hormones.
5)When the Cells have divided and grown into a small plant, they’re taken out of the medium and planted in soil
What are the positives of artifical cloning?
- Desirable genetic characteristics are always passed on to clones. This doesn’t always happen when plants reproduce sexually.
- Tissue culture allows plants to reproduce in any season because the environment is controlled.
- Less space is required by tissue culture .
- Lots of plants are produced very quickly compared with growing plants from seeds.
- Using the apical bud(merristems) as an explanation ensures that the new plants are free from viruses
What are the disadvantages of artifical cloning?
- Undesirable genetic characteristics are always passed on to clones.
- Cloned plant populations have no genetic variation, so a single disease could kill them all.
- Production costs of tissue culture are very high due to high energy use and the training of skilled workers.
- Contamination by microorganisms during tissue culture can be disastrous and result in a complete loss of the plants being cultured.
What is an example of natural clones in animals?
Twins
What are the methods of artifical cloning in animals?
Artifical embryo twinning AND Somatic cell nuclear transfer
Describe the process of Artificial embryo twinning
1) An egg cell is extracted from a female cow and fertilised in a petri dish.
2) The zygote(the fertilised ehg) is left to divide by mitosis to form an embryo .
3) Next, the individual cells from the embryo are separated and each put into a separate petri dish. Each cell divides and develops normally, so an embryo forms in each petri dish
4) The embryos are then implanted into female cows which act as surrogate mothers.
5) The embryos continue to develop inside the surrogate cows and eventually offspring are born.
All the offspring will be genetically identical to one another
Describe the process of somatic cell nuclear transfer
1) A somatic cell (any cell that isnt reproductive) is taken from Sheep A to be cloned and its nucleus is removed.
2) An immature egg cell is taken from sheep B and the nucleus is removed, enucleation.
3) The nucleus from sheep a is inserted into the enucleated egg cell. The egg cell from sheep B now contains the genetic information from sheep A.
4) The nucleus and the enucleated egg cell are fused together and are stimulated to divide by an electric shock.
5) The shock also triggers the egg cell to start developing as though it has just been fertilised. This produces an embryo
6) The embryo is then implanted into the uterus of a surrogate mother. Eventually a lamb is produced that is a clone of Sheep A.
What are the uses of animal cloning ?
- Research purposes.
- Saving endangered animals from extinction
- Farmers increasing the number of animals with desired characteristics
- GM animals could produce useful substances that they wouldn’t normally produce
- Embryonic stem cells can be cloned and these could be used to replace damaged tissues
What are the advantages of animal cloning?
- Desirable genetic characteristics are always passed on to clones, which doesn’t always happen with sexual reproduction.
- Infertile animals can be reproduced.
- Increasing the population of endangered species helps to preserve biodiversity.
- Animals can be cloned at any time, you don’t have to wait till breeding season
- Cloning can help us develop new treatments for disease, which could mean less suffering for certain people.
What are disadvantages of animal cloning?
- Animal cloning is very difficult, time consuming and expensive.
- There’s no genetic variation in cloned populations so undesirable genetic characteristics are always passed on. This means that all the cloned animals in a population are susceptible to the same diseases.
- Some evidence suggests that clones may not live as long as natural offspring.
- Using cloned human embryos as a source of stem cells is controversial. Some people see it as the loss of a human life
What is biotechnology?
Biotechnology is the industrial use of living organisms to produce foods, drugs and other products
Why are microorganisms used for biotechnology?
- Their ideal growth conditions can be easily created, they’ll generally grow successfully if they have the right nutrients, temperature, pH, moisture levels, and availability of gases.
- Because of their short life cycle, they grow rapidly and so products can be made quickly.
- They can be grown on a range of inexpensive materials, this makes their use economically viable
- They can be grown at any time of the year.
What are intracellular enzymes?
Enzymes contained within cells
What are isolated enzymes?
- ## enzymes that aren’t contained within cells.
What would allow a population to grow exponentially?
A lack of limiting factors
What is the exponential growth phase during bacteria growth?
where the bacteria population doubles every 20 minutes (2^n)
what happens before the exponential growth phase?
the lag phase
what happens during the lag phase?
the bacteria is climatising and synthesising enzymes
what happens during the stationary phase?
the limiting factors are slowing down the growth of the bacteria
give some examples of the roles of microorganisms in industry
- brewing
- baking
- cheese making
- yogurt production
- penicillin production
- insulin production
- bioremediation
what are the advantages of using microorganisms to make food for human consumption?
- Microorganisms used to make proteins can be grown using many different organic substrates, including waste materials, such as molasses.
- Microorganisms can be grown quickly, easily and cheaply. Production costs are low because microorganisms have simple growth requirements, can be grown on waste products and less land is required in comparison to growing crops or rearing livestock.
- Microorganisms can be cultured anywhere if you have the right equipment. This means that a food source could be readily produced in places where growing and rearing livestock is difficult.
- Single-cell protein is often considered a healthier alternative to animal protein
what are the disadvantages of using microorganisms to make food for human consumption?
- Because the conditions needed to grow the desired microorganism are also ideal for other microorganisms, a lot of effort has to go into making sure that the food doesn’t get contaminated with unwanted bacteria.
- People may not like the idea of eating food that has been grown using waste products.
- Single-cell protein doesn’t have the same taste as normal meat.
- Over-consumption of single-celled protein can cause health issues
what is a culture?
a population of one type of microorganisms that’s been grown under controlled conditions
Where are cultures grown?
In large containers called fermentation vessels
What are the 2 main methods for culturing microorganisms?
Batch fermentation and continuous fermentation
What is batch fermentation?
- Where microorganisms are grown in individual batches in a fermentation vessel.
- When one culture ends, it’s removed and then a different batch of a microorganism is grown in the vessel
- This is known as closed culture
How is pH regulated in a fermentation vessel?
- By a pH probe which keeps the pH at an optimum level.
How is temperature regulated in a fermentation vessel?
- By a water jacket that surrounds the entire vessel
How is the access to nutrients regulated in a fermentation vessel?
- Paddles constantly circulate fresh nutrient medium around the vessels.
How is the volume of oxygen regulated in a fermentation vessel?
By pumping sterile air into the vessel when needed
How can a sterile vessel be regulated?
By passing superheated steam through the vessel after each use
How does regulating the pH and the temperature help to achieve the maximum yield?
Because it allows the enzymes to work effectively, so the rate of reaction is kept as high as possible.
How does regulating the access to nutrients help to achieve the maximum yield?
Because it ensures that the microorganisms always have access to their required nutrients
How does regulating the the sterility of the vessel help to achieve the maximum yield?
Because it helps kill any unwanted organisms that may compete with the ones being cultured
What is the formula for the number of individual organisms?
N= N0 ×2^n
Is it true that the population size stays level because the death rate of the microorganisms equals their reproductive rate during the stationary phase? And that microorganisms die because there’s not enough food and poisonous waste products build up?
Yes
What happens during the decline phase?
The population size falls because the death rate is greater than the reproductive rate. This is due to food being very scarce and waste products being at very toxic levels
How are microorganisms cultured in a lab?
- Microorganisms are transferred to the agar plate from a sample using a sterile inoculation loop.
- The plates are then incubated to allow the Microorganisms to grow.
- Nutrients can be added to the agar to help improve the growing conditions
What techniques are used when culturing microorganisms?
Aseptic techniques because this helps prevent contamination
What is an autoclave?
A machine that steams equipment at high pressure
Describe some aseptic techniques used when culturing microorganisms
- Regularly disinfect work surfaces to minimise contamination
- Work near a bunsen flame. This is because hot air rises, so any microorganisms in the air can be drawn away from the culture.
- Sterilise the inoculating loop by passing it through a hot Bunsen burner flame.
- If you’re using broth, briefly pass the neck of the broth container through a Bunsen burner flame just after it’s opened and just before it’s closed.
- Minimise the time that the agar plate is left open for. This reduces the chance of airborne microorganisms contaminating the culture
- Sterilise all glassware before and after use using an autoclave for example.
- Wear a lab coat and gloves. Tie long hair back
Describe a practical that could be used to measure the effects of temperature on the growth of bacteria
How are enzymes immobilised?
By being attached to or located within an insoluble support
What are the methods of enzyme immobilisation?
1) Adsorption
2) Covalently bonded to cellulose or collagen fibres
3) Entrapment in a silica gel matrix
4) Membrane separation
5) Direct cross-linking
What are the advantages of enzyme immobilisation?
- Enzyme can be re-used so reduces cost.
- The product will be purer.
- Immobilised enzymes work at higher temperatures, so reraction will have a higher yield.
- Immobilised enzymes aren’t denatured by pH changes.
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What are the disadvantages of enzyme immobilisation?
- Immobilisation may alter she shape of the enzyme
- Reaction rates may decrease as enzymes have less direct contact with the substrate.
- Expensive and lengthy to set up
Give some examples of industrial processes where immobilised enzymes are used
- Glucose isomerase for the conversion of Glucose to fructose.
- Penicillin acylase for the formation of semi-synthetic Penicillins
- Lactase for the hydrolysis of lactose to Glucose and galactose
- aminoacylase for the production of pure samples of L-amino acids.
- glucoamylase for the conversion of dextrous to Glucose
What is a primary metabolite?
- A molecule needed for the cell’s normal growth and development, for example, glucose.
When are most primary metabolites produced?
During the exponential phase
