Cloning and Biotechnology, 6.4 Flashcards
(79 cards)
1
Q
What is a clone?
A
A genetically identical organism
2
Q
How can clones be produced in nature?
A
Asexual reproduction or twins
3
Q
What are some advantages of Natural Clones?
A
- If conditions are good for the parents they will be good for the offspring
- Relatively rapid
- Can be carried with only one parent
4
Q
What are some of the disadvantages of Natural Clones?
A
- Offspring become overcrowded
- No genetic diversity
- Population shows little variation
- Selection is not possible
- Entire population vulnerable to environmental changes
5
Q
What is vegetative propagation?
A
Reproduction from vegetative parts of a plant - usually an overwintering organ
6
Q
What is special about plant cells?
A
Many parts of the plant contain cells with the ability to divide and differentiate into a wide range of cells
7
Q
What are runners, stolons, rhizomes and suckers?
A
- Plants grow horizontal stems that can form roots at certain points
- Underground thick growth at nodes, rhizomes
- Overground, runners and stolons
- New stems that grow from the root, suckers
8
Q
What are bulbs?
A
- An underground stem which will grown into a new plant
- More than one apical bud
9
Q
What are Tubers?
A
- Swollen part of an underground stem
- Can be cut into pieces which will grow into new plants
- Potatoes
10
Q
What are Corms?
A
- Food store in stem tissue
- Solid, underground
- Can divide to produce more identical plants
11
Q
What natural clones can be produced by animals?
A
Identical twins. Water flee and greenfly reproduce asexually
12
Q
How are identical twins formed?
A
- Egg feritilised to form a zygote
- Zygote divides into two separate embryos
13
Q
How can plants be cloned from cuttings?
A
- Stem cut between two leaf joints (nodes)
- The cut end is placed in soil
- New roots will grow from the stem
- Can produce large numbers quickly
- Usually dipped in rooting hormone
14
Q
What is tissue culture?
A
Growing new tissues or organs from a sample plants tissue
15
Q
What is micropropagation?
A
Growing a large number of new plants from meristem tissue taken from a sample plant
16
Q
What are the stages of micropopagation?
A
- Plant material selected and cut into small pieces - called explants
- Explants sterilised in alcohol
- Placed on a sterile growth medium using suitable nutrients and growth hormones
- Cells divide and form a callus
- Callus divides to produced a larger number of small clumps of undifferentiated cells
- These clumps are stimulated to grow, divide and differentiate
- Tiny plantlets are formed and grown in a greenhouse
17
Q
What are the advantages of micropropagation?
A
- Rapid production
- Carried out even if sexual reproduction is not possible
- Offspring will display desirable characteristics
- Uniform phenotype is easy to grow and harvest
18
Q
What are the disadvantages of micropropagation?
A
- Labour intensive
- Expensive
- Can fail due to microbial contamination
- Will be susceptible to the same diseases
- No genetic variation
19
Q
What are totipotent cells?
A
Cells that can divide and differentiate into all types eg embryo cells
20
Q
What is reproductive cloning?
A
Produce large numbers of genetically identical animals through reproduction
21
Q
What can reproductive cloning be used for?
A
Produce elite farm animals. Reproduce genetically modified animals with unusual characteristics
22
Q
What is embryo twinning?
A
Splitting of an embryo. If an embryo splits early it can produced identical offpsring
23
Q
What are the different stages of embryo twinning
A
- Zygote created by IVF
- Zygote is allowed to divide by mitosis to create a small ball of cells
- Cells are separated and allowed to continue dividing
- Each small mass of cells is placed into a surrogate
24
Q
When is the phenotype of the clone know during embryo twinning?
A
After the animal is born
25
What is Somatic Cell Nuclear Transfer?
Transferring the nucleus of a somatic cell to an egg cell. Only way to clone an adult.
26
What are the stages of Somatic Cell Nuclear Transfer?
1. Egg cell obtained and nucleus removed
2. Somatic cell isolate, may have the nucleus removed
3. Somatic cell or nucleus is fused with the egg cell by applying an electric shock
4. Shock triggers the egg cell to start developing
5. Undergoes mitosis to produce a small ball of cells
6. Embryo is placed in a surrogate mother
27
When is the phenotype known during Somatic Cell Nuclear Transfer?
Before cloning
28
What is non reproductive cloning?
The production of cloned cells and tissues for uses other than reproduction
29
What are some examples of therapeutic cloning?
- Skin grow in vitro to act as a graft
- Cloned cells have been used to repair damage to spinal cord of a mouse
- Potential to grow new organs
30
What are the advantages of cloning animals?
- Produce large numbers of high value animals
- Can research the actions of genes and hormones
- Can test drugs
- Produce new organs, skin and other tissue
- Rare animals can be preserved
- Scientific testing, avoids using animals
31
What are the disadvantages of cloning animals?
- Lack of genetic diversity
- Animals produced with little regard for welfare
- Success rate is poor
- Long term affects unclear
- Ethical issues
32
What is biotechnology?
Use of living organisms or parts of living organisms in industrial processes
33
What is included in biotechnology?
- Gene technology
- GM
- Selective breeding
- Immunology
- Use of enzymes
34
What microorganisms are use to produce food?
- Ethanol, yeast
- CO2 in bread rising, yeast
- Lactic acid for yogurt and cheese, lactobacillus bacteria
- Soya beans fermented, yeast
35
What microorganisms are used to produce drugs?
- Penicillin, fungus
| - Insulin (GM bacteria)
36
What microorganisms are used for enzymes?
- Washing powders, protease and lipase
- Extract juice, Pectinase
- Digest sugar to make food sweeter, yeast
37
What are some advantages of biotechnology?
- Microorganisms are cheap and easy to grow
- Production can take place at lower temperatures
- Not dependent on the climate
- Microorganisms can reproduce in less than 30mins
- Tend to generate more pure products
- Can be genetically modified easily
- Fewer ethical considerations
- Fed using by products so less waste
38
How is biotechnology used to make yogurt?
- Milk undergone fermentation
- Bacteria converts lactose to lactic acid
- The lactic acid denatures the milk protein, it coagulates
- Bacteria partially digests the milk
- Produces the flavour of yogurt
39
How is biotechnology used to make cheese?
- Bacteria converts lactic acid to lactose in milk
- Once acidified milk is mixed with rennet (contains renin) and coagulates the milk protein in presence of calcium ions
- Kappa-casein is broken down. Makes casein insoluble
- Casein precipitated by the action of calcium ions binding the molecules together
- The resulting solid (curd) separates from the liquid
- Curd is passed into moulds
- Treatment while making and pressing the curd determines characteristics of the cheese
40
How is biotechnology used in baking?
- Bread is a mixture of flour, water and salt with some yeast
- Mixing by kneading forms dough
- Fermenting, yeast respires producing CO2 causing the dough to rise
- Cooking, risen dough is baked
41
How is biotechnology used in alcohol?
- Product of yeast respiring
- Wine grapes have yeast on their skin
- Ale/beer, brewed using barley grains that are beginning to germinate
- Anaerobic respiration produces CO2 and alcohol
42
What are some advantages of biotechnology?
- Protein produced faster than animals/plants
- Production can be easily increased or decreased according to demand
- No animal welfare issues
- Protein contains no cholesterol or fat
- Easily genetically modified
- Independent of seasons
43
What are some disadvantages of biotechnology?
- Unappetizing
- Isolation of the protein
- Protein needs to b purified
- Amino acid profile may be different from animal protein
- Risk of infection
- Poor palability
44
How do commercial drug producers scale up production?
Use large stainless steel containers (fermenters). Growing conditions can be controlled to get the best yield
45
What conditions do microorganisms need to survive?
1. Temperature - optimum temperature, denature if too hot
2. Nutrients and respiratory substrates
3. Need space
4. Supply of oxygen to respire
5. Optimum pH
46
How are conditions controlled in a fermenter?
1. Water jacket - circulation of water
2. Inlet for the addition of nutrients
3. Sparger, filtered air inlet needs to be steriliesed
4. pH control reservoir
5. A motor to mix the contents
47
What is batch fermentation?
- In a close fermenter
- Has a nutrient medium and is left for fermentation to take place
- Can maintain culture in stationary phase to proude secondary metabolites
- Product is separarted from the mixture at the end
- Waste gases removed
- All nutrients are depleted at the end
- Temperature controlled
48
What are the advantages of batch fermentation?
- The same each time
- Easy to set up and control internal factors
- Vessels are versatile
- Easier to meet market demand
49
What is continuous fermentation?
- Open fermenters
- Nutrients continuously added and waste products removed
- Maintains microorganisms in the log phase
- Vital to monitor environment
50
What are the advantages of continuous fermentation?
- Process is more productive
- Smaller vessels
- Cost effective
51
What are the disadvantages of continuous fermentation?
- Problem with foaming, clumping of cells
- If it breaks down it would be costly
- Difficult to monitor all the environmental factors
52
What technique needs to be used when handling and culturing bacteria?
Aseptic tehcnique
53
What does asepsis mean?
Ensure sterile conditions are maintained
54
What are some examples of aseptic technique?
- Draught free area
- Surfaces washed with antiseptic
- Flame the tops of bottles and culture vessels
- Use sterile pipettes and flamed loops
- Culture medium and agar plates are sterile
- Incubate in a sealed incubator never above 30degrees
55
How was penicillin mass produced through fermentation?
1. Fermentation run for 6-8 days. Culture is then filtered to remove the cells
2. Antibiotic is precipitated as crystals by the addition of potassium compounds
3. Antibiotic may be modified by the action of other microorganisms or chemicals
4. Antibiotic mixed with inert substances and prepared for administration
56
What is bioremediation?
Use of microorganisms to clean the soil and underground water on polluted sites - convert pollutants into less harmful substances
57
How does bioremediation work?
- Stimulates the growth of suitable microbes that use contaminants as a source of food
- Conditions need to have available water, suitable temperature and suitable pH
58
What are the advantages of bioremediation?
- Uses natural systems
- Less labour/equipment needed
- Treatment in situ
- Few waste products
- Less risk of exposure
59
What is sterilization and how do we use it in microbiology?
- Agar medium and any equipment must be sterilised
- Medium sterilised in an autoclave at 121 for 15 mins
- Lid is kept on the petri dish
60
What is Inoculation and how do we use it in microbiology?
- Introduction of microorganisms to the sterile medium
- Streaking - drop of liquid dragged by the loop
- Seeding - sterile pipette
- Spreading - sterile glass spreader
- Small cotton swab - collect microorganisms from surfaces
61
What is incubation and how do we use it microbiology?
- Petri dish labelled and the top taped to the bottom
- Placed in warm environment
- Placed upside down to prevent drops falling on the surface
- Cultures examined after 24 hours
- Do not open petri dish
62
What are serial dilutions?
Sequence of dilutions used to reduced the concentration of a solution or suspension
63
Why might we need to use serial dilutions?
Too many cultures may be merged on an agar medium to count
64
How do we carry out serial dilutions?
- Take 1cm3 and add 9cm3 of distilled water
- Take 1cm3 of this add 9cm3 of distilled water
- Continue this
65
What is the lag phase in the bacterial growth curve?
- Little increase in cell numbers
- Have to adjust to environment, bacteria inactive
- May need to produce new enzymes
- Have to start reproducing asexually
- Taking up the nutrients
66
What is the log phase in the bacterial growth curve?
- Bacteria multiply rapidly
- Conditions are perfect: lots of nutrients, no waste, no space, correct nutrients
- They have adjusted
- Birth rate is greater than death rate
67
What is the stationary phase in the bacterial growth curve?
- Remains stable
- Birth rate and death rate are equal
- There are now limiting factors
- Waste is building up affecting pH
- Resources running low
- Secondary metabolites produced
68
What is the death phase in the bacterial growth curve?
- Decline in population
- Death rate is higher than birth rate
- Too much waste becomes lethal
- Concentration of nutrients is low
69
What are Primary Metabolites?
- Produced during the normal activities of an organism
- Produced during log phase
- Collected in a fermenter (not a closed culture)
- Substances such as amino acids, lipids, vitamins
70
What are Secondary Metabolites?
- Substance not produced as part of normal growth
- Produced during the stationary phase
- Population in a closed culture
- Substances - Penicillin, anitbiotics
71
What are immobilised enzymes?
Enzymes that are help in place and not free to diffuse through the solution
72
How do immoblised enzymes work?
- Attached to insoluble materials act as a support
| - Enzymes held in place, removed after and reused
73
What are the advantages of immoblising enzymes?
- Enzymes do now mix with product so lower extraction cost and can be used again
- Product will not be contaminated by the enzyme as the enzyme is held in a matrix
- Enzymes is protected by the matrix so more stable at extreme temperatures and pH's
- Controlled more accurately
74
What are the disadvantages of immoblising enzymes?
- More expensive to set up
| - Immobilised enzymes are less active so the reaction will therefore be slower
75
Describe how we immobilise enzymes by adsorption?
- Bound to a supporting surface by hydrophobic interactions and ionic links
- eg clay, porous carbon, glass beads, resins
- Bound with active site exposed, however, the active site may be distorted by extra bonds
- Bonds are weak and enzymes could break free
76
Describe how we immobilise enzymes by covalent bonding?
- Bound to a support surface by covalent bonds
- Bonded with a cross-linking agent
- Expensive and can distort enzymes active site
- Strong bonds so unlikely to detach
77
Describe how we immobilise enzymes by entrapment?
- Trapped in a matrix that does not allow free movement
- Enzymes unaffected and remain fully active
- Substrate has to diffuse into the matrix
- Substrate and product must be small
- eg Calcium alginate beads
78
Describe how we immobilise enzymes by membrane separation?
- Enzymes separated from reaction mixture by a partially permeable membrane
- Substrate and product molecules must be small enough to diffuse through
- Access to enzymes may limit reaction rate
79
What are some industrial uses of immobilised enzymes?
- Glucose isomerase: converts glucose to fructose, produces high levels of fructose, sweeter than sucrose but less sugar
- Lactase: converts glucose to lactose by hydrolysis, produces lactose free milk, can be drunk by lactose intolerant people and they can still get calcium
