Cloning And Biotechnology - Module 6 Flashcards
1
Q
What is asexual reproduction a form of?
A
Cloning - produces genetically identical clones to parent organism and other offspring
2
Q
What is the name of natural cloning?
A
Vegetative propagation
3
Q
What are perennating organ?
A
Stores containing food from photosynthesis so that they can remain dormant in soil
4
Q
What are the 4 structures that plant clones occur in?
A
- Bulbs
Leaf base swells with assimilates and develops into new shoots - Runners
Lateral stem grows away from parent plant and roots develop where it reaches ground - Rhizomes
- Stem Tubers
5
Q
How are bulbs, runners and rhizomes exploited by horticulturists to produce new plants?
A
Bulbs are split, runners are removed from parent plant and rhizomes are cut
They increase the number of plants cheaply as well as maintaining genetic characteristics
6
Q
How are cuttings made from plants? [2]
A
- Short sections of stem are taken and planted into the ground or pots
- Rooting hormone powder is often applied encourage new growth
7
Q
How is propagation from cuttings advantageous over planting seeds?
A
- It is much faster
- Guarantees quality of plant as it will be an exact clone of the parent plant
8
Q
What is a disadvantage of using cuttings over seed propagation?
A
There is a lack of genetic variation and therefore if a new disease of pest appears it may wipe out all plants
9
Q
Many plant cells are totipotent.
What does this mean?
A
They can differentiate into all of the different cells needed in the plant
10
Q
What is micropropagation?
A
The process of making large numbers of genetically identical offspring from a single parent using tissue culture techniques
11
Q
In what circumstance is micropropagation used? [5]
A
- Plant doesn’t produce seeds
- Plant doesn’t respond well to natural cloning
- Plant is rare
- Plant has been genetically modified
- Required to be pathogen free
12
Q
Describe the process of micropropagation
A
- Take a small sample of tissue from plant that you want to clone (this is the explant)
- Sample is sterilised in bleach/ethanol
- Explant is placed in a sterile culture medium containing Plant hormones for mitosis
- A mass of identical cells form called a callus
- The callus is divided up and transferred to new medium which promotes development
- Plantlets are placed into compost
13
Q
What are the advances of micropropagation?
A
- Allowed for rapid production of crops we know will have a good yield
- Produces disease free plants
- Increases numbers of rare and endangered plants
14
Q
What are the arguments against micropropagation? [4]
A
- Produces monoculture - many plants are genetically identical
- Expensive process requiring skilled workers
- Plantlets and explant are vulnerable to infection
- If source is infected ALL CLONES WILL BE INFECTED
15
Q
In vertebrate animals, what is a form of cloning?
A
Monozygotic twins (identical twins)
16
Q
What animals clone more commonly? Give an example.
A
Invertebrates
E.g starfish can regenerate a whole new animal from fragments of the original
17
Q
How does cloning occur in vertebrates?
A
Early embryo splits to form two seperate embryos
18
Q
What are the two methods use to clone mammals?
A
- Artificial twinning
- Somatic cell nuclear transfer
19
Q
When an egg is fertilised, a ball of cells is formed.
What is a characteristic of these cells?
A
They are totipotent
20
Q
How is artificial twinning similar to natural twinning?
A
In both the embryo splits - just in artificial twinning it is done manually
21
Q
Who uses artificial twinning?
A
Used by the farming community to produce the maximum offspring from particularly good dairy or beef cattle/sheep
22
Q
Describe the stages of artificial twinning?
A
- Cow with the desirable traits is tried with hormones so she SUPER OVULATES (releases more eggs than usual)
- The eggs are fertilised (either naturally or artificial inemination) by a bull with desired traits
- Early embryos removed from uterus
- Whilst still totipotent the cells of the early embryo are split to produce smaller embryo’s
- Split embryos are implanted into different surrogate mothers
- Lots of little cow clones born
23
Q
How does artificial twinning differ in pigs to cows?
A
In pigs lots of embryos need to be implanted into surrogate as they are used to carrying a litter of piglets
In cows singular pregnancies are more successful
24
Q
What does artificial twinning clone?
A
Embryos
25
What does somatic cell nuclear transfer clone?
Adult animals
26
What is an example of somatic cell nuclear transfer?
DOLLY THE SHEEP IN 1996
27
Describe the steps of somatic cell nuclear transfer?
1. Nucleus is removed from a somatic cells of adult animal
2. Nucleus is removed from a mature egg taken from a DIFFERENT FEMALE OF SAME SPECIES
3. Nucleus from adult somatic cell is placed into mature enucleated egg cell
4. New cell is given an electric shock to fuse and begin to divide
5. Embryo will develop and is transferred into nucleus of a third animal which will be carried to term
6. New animal is clone of original adult animal
28
Name some arguments for Animal cloning
1. Artificial twinning allows high yeilding farm animals to produce more offspring than normal reproduction
2. SCNT allows scientist to clone specific animals
3. SCNT has the potential to enable rate, endangers and extinct animal to be reproduced
29
Name some arguments against animal cloning
1. Cloned animals embryos often fail and either miscarry or produce deformed offspring
2. Cloned animals often have shortened life spans
30
What is biotechnology?
The use of biological organisms to the synthesis, breakdown or transformation of materials in the service of people
31
What are the most commonly used organisms in biotechnology?
Fungi, Yeats and bacteria
32
What are microorganism ideal in biotechnology?
1. No welfare issues to consider
2. Range of microorganisms for different functions
3. Rapid growth rate
4. Nutrient requirement are often simple and cheap
33
What are some disadvantages of using microorganisms in indirect food production? [2]
1. If conditions are not ideal they wont work
2. Conditions ideal for microorganism may be ideal for making food go off
34
what microorganism is involved with baking?
Yeast - as it respire aerobically to make carbon dioxide letting dough rise
35
How is bread produced commercially?
Yeast mixture is added to ingredients, mixed and left to rise
It is then cooked in a hot oven - bred will ruse due to expansion of carbon dioxide bubbles
36
What happens to yeast during the baking of bread?
It is killed by the temperature
37
What microorganism is used in brewing?
Yeast - as it respired anarobically to produce ethanol
38
What are the steps in commercial brewing?
1. Malting - enzymes produced by barley to break down sugars for yeast. Malt is produced.
2. Mashing - malt is mixed with hot water and hops added
3. Fermentation - yeast added and eventually inhibited by concentration of ethanol
4. Beer is matured, filtered and distributed
39
What microorganism is used in cheese making?
Bacteria
40
Describe the process of cheese commercial making
1. Milk is pasteurised (kill natural bacteria) and homogenised (fat droplets evenly distributed)
2. Milk mixed with bacterial cultures and kept until separated into curds and whey
3. Curds are cut and cooked in the whey and strained
4. Curds are left to mature
41
What microorganism is used in the commercial production of yoghurt ?
Bacteria
42
Describe the stages of commercial yoghurt production
1. Skimmed milk powder is added to milk and pasteurised and homogenised, and then cooled
2. Milk is mixed with bacteria and incubated for a few hours
3. Yoghurt is split into containers
4. Thick set yoghurt is left to ferment in pot
43
What is SCP?
Single cell protein
Microorganism that can be eaten directly as a protein source
44
What is the best know source of SCP?
QUORN
45
How is quorn made?
Using a fungus, it is grown in a fermenter using glucose syrup
Then it is combined with egg white, compressed and formed into meat substitutes
46
What is an increasing use of SCP’s?
Feeding animals that we prefer to eat from fish to cattle
47
List the advantages of using microorganism to produce human food
1. Faster reproduction than animals
2. High protein with little fat content
3. Can use waste materials
4. Not dependent on weather
5. No welfare issues
48
List the disadvantages of using microorganisms in food production
1. Toxins produced if conditions not maintained
2. Need carefully controlled sterile conditions (expensive)
3. Little flavour, needs additives
49
How is penicillin produced?
Using a semi continuous batch process the fungus will grow in the medium produce penicillin and then finally it will be extracted from the medium and purified
50
List the conditions needed for penicillin production
1. Continuously stirred to maintain oxygenated
2. Rich nutrient medium
3. Buffer solution required to maintain pH
4. Maintain temperature at 25 degrees
51
List the issues associated with animal insulin
1. Supply and demand was an issue
2. Allergies
3. Religious complications as it came from pig
52
What is bioremediation?
The use of microorganism to break down pollutants and contaminate in the soil or water
53
What are the two approaches to bioremediation?
1. Using natural organisms
2. Using GM organisms
54
Where does bioremediation occur?
On the site of contamination
55
How are GM organism used in bioremediation?
They are used to break down contaminants which would not usually encounter an organism that can break it down e.g mercury
56
Why are microorganisms cultured?
To investigate the use of microorganisms for the medical diagnosis or disease/ science experiments
57
What are the risks involved with using microorganisms that we may assume are completely harmless in the laboratory?
1. Risk of mutation making microorganism pathogenic
2. Contamination with pathogenic microorganism from the environment
58
What conditions need to be maintenance to culture microorganisms?
1. Temperature
2. Oxygen
3. PH
59
What is the nutrient medium in culturing microorganisms?
The food provided form microorganisms
60
What two forms can the nutrient medium be in form microorganisms?
1. Solid (agar)
2. Liquid (broth)
61
Describe the process of inoculating broth in culturing microorganisms
1. Make a suspension of bacteria to be grown
2. Mix a known volume with sterile nutrient broth in flask
3. Stopper the flask with cotton wool to prevent contamination from air
4. Incubate at a suitable temperature, shaking regularly to aerate the broth giving oxygen to growing bacteria
62
What is inoculation?
The addition of bacteria to the nutrient broth in cultuing microorganisms
63
Describe the steps to inoculate agar
1. Sterilise inoculating loop in Bunsen
2. Dip sterilised loop in bacterial suspension
3. Remove Petri dish lid and make zigzag steak across agar (avoid digging into agar)
4. Replace lid of Petri dish (taped, but not all the way for aerobic conditions)
64
What are the 4 stages of the bacterial growth curve?
1. Lag phase
2. Log phase
3. Stationary phase
4. Decline stage
65
What is the lag phase?
When bacteria are adapting to new environment, growing at a slow rate
66
What is the log phase?
When rate of bacterial growth is at theoretical maximum
67
What is the stationary phase?
Total growth rate is zero, as new cells formed is cancelled out by cells dying
68
What is the decline stage?
When reproduction has ceased and death rate of cells is increasing
69
What are the limiting factors which prevent exponential growth in a culture of bacteria?
1. Nutrients available
2. Change in pH (enzymes)
3. Oxygen
4. Temperature (enzymes)
5. Build up of waste
70
What are the advantages of using isolated enzymes?
1. Less wasteful
2. More efficient (higher concentrations)
3. More specific
4. Less downstream processing as pure product is made by enzymes
71
What type of enzyme are used in isolated enzyme use?
Extra cellular
72
Why are extracellular enzymes more advantageous than intracellular enzymes?
1. They are excreted so easy to isolate and use
2. Easily identifiable as organism produce fewer than intracellular enzymes
3.extracellular tend to be more robust so they are able to adapt to variations of temperature and pH
73
Despite the advantages of extracellular enzymes, why are intracellular enzymes still used?
There is a greater range and may provide the desired enzyme `
74
Despite isolated enzymes being more efficient, why are they wasteful?
1. Lost at the of the process
2. Not cheap to produce
75
What are the advantages of immobilised enzymes? [3]
1. Can be reused (cheaper)
2. Easily separated from reactant and products
3. Grater temperature tolerance
76
What are the disadvantages of using immobilised enzymes?
1. Reduced efficiency (slows down process)
2. Higher initial costs of materials
3. Have to have a bioreactor
4. More technical issues as bioreactors are more complex than fermenters
77
What is an immobilised enzyme?
An enzyme attached to an inert support system
78
What are the different ways an enzyme can be immobilised? [3]
1. Bound to surface by adsorption or covalent bonds
2.entrapped in a matrix
3. Behind semipermeable membrane
79
What are the advantages of surface adsorption of immobilising enzymes?
1. Easy and cheap
2. Enzyme very accessible to substrate, activity unaffected
80
What are the advantages of surface covalent bonding of immobilising enzymes?
1. Strongly bound so enzymes unlikely to be lost
2. Accessible to substrate
3. PH will have little affect on enzyme activity
81
What are the advantages of entrapment In a matrix of immobilising enzymes?
1. Applicable to lots of different processes
2. Simple
82
What are the disadvantages of using surface adsorption for immobilised enzymes?
Enzymes can be lost from matrix easily
83
What are the disadvantages of using entrapment matrix for immobilised enzymes?
1. Can be expensive
2. Difficult
3. Diffusion of substrate to and the product from the active site can be slow
84
What are the disadvantages of using membrane entrapment for immobilised enzymes?
1. Expensive
2. Slow diffusion to and product from the active site can be slow and hold up the reaction
85
What are the advantages of using membrane entrapment for immobilised enzymes?
1. Simple to do
2. Small effect on enzyme activity
86
What are the advantages of immobilising whole microorganisms?
Avoids process of tracing enzyme
87
What are the disadvantages of immobilising whole organisms?
The organisms need food, oxygen and a controlled environment to maintain optimum
88
What is the use of immobilised penicillin acylase?
Used to make semisynthetic penicillin from natural penicillin, as many bacteria are not resistant to semi synthetic versions of penicillin
89
What is the use of immobilised glucose isomerase?
Used to produce fructose from glucose as it is much sweeter and widely used as a sweetener in the industry
90
What is the use of immobilised lactase?
Used to produce lactose free milk, it hydrolyses lactose to galactose making milk lactose free
91
What is aminoacylase used for?
Producing pure samples of L-amino acids used for pharmaceuticals, cosmetics and food
92
What is immobilised glucosamylase used for?
Used to complete the breakdown of starch to glucose syrup, the final breakdown of dextrins to glucose
93
What is the use of immobilised nitrile hydratase?
To convert acrylonitrile to acrylamide which is used in the plastic industry
94
What is batch fermentation? [4]
Microorganisms are inoculated into a fixed volume of medium, as growth takes place the nutrients are used up and both new biomass and waste product build up
The culture will reach the stationary phase, microorganisms carry out biochemical changes to form the desired end product
The process is stopped before death phase and products are harvested
95
What is continuous culture?
Microorganisms are inoculated into a sterile nutrient medium and will beginning to grown
The sterile nutrient medium is added continually until it reaches the log phase (exponential growth)
Culture broth is continually removed - the culture volume in the bio reactor is constant
96
What is continuous cultivation used for?
Production of SCPs and waste water treatment
97
What factors need to be controlled in bioreactors?
1. Temperature
2. Nutrients and oxygen
98
Why do bioreactors have mechanisms that continuously stir the mixture?
So that all the microorganisms receive enough food and oxygen remaining at the correct temperature
99
Why are bioreactors sealed?
So they remain aseptic as contamination can seriously affect the yield
100
What is the calculation for the number of cells in a population?
Number of cell in population = initial number of cells x 2^n
101
What is a primary metabolite?
A product made from the beginning of the reaction
102
What is a secondary metabolite?
Usually produced through the modification of primary metabolites
