6.4 Cloning and Biotechnology Flashcards
1
Q
Define clones
A
Genetically identical organisms or cells
2
Q
Define vegetative propagation
A
Reproduction from vegetative parts of a plant - usually an over- wintering organ.
3
Q
Advantages of natural cloning
A
- if conditions are good for parent, they will be good for offspring
- rapid, take advantage of good conditions
- reproduction only with one parent
4
Q
Disadvantages of natural cloning
A
- offspring may be overcrowded
- no genetic diversity
- little variation
- selection is not possible
- who population endangered with changes in environment
5
Q
What are rhizomes?
A
stem structures that grow horizontally underground away from the parent plant. they have nodes from which new shoots and roots can develop
6
Q
What are suckers?
A
New shoots that grow from the roots of a plant
the original branch may die and leave it as a separate individual stem
7
Q
What are stolons ?
A
Also known as runners, horizontal stem structures that grow away from the plant above ground.
8
Q
What are tubers?
A
large underground plant structures that act as a food store for the plant.
9
Q
What are bulbs?
A
Underground food stores. New bulbs can develop from the original bulb and form new plants
10
Q
Example of rhizomes
A
Bamboo
11
Q
Example of Stolon
A
Strawberries
12
Q
Example of sucker
A
Elm trees
13
Q
Example of tubers
A
potato
14
Q
Example of bulb
A
onions
15
Q
How to form cutting
A
1) use scalpel to take cutting from parent plant
2) remove leaves from lower end, leaving one
3) dip lower end in rooting powder (with hormones)
4) put in growth medium
5) warm moist environment ( plastic bag or propagator)
6) plant elsewhere when strong enough
16
Q
Explain tissue culture
A
1) cells taken OG plant (from stem and root tips bc stem cells)
2) sterilised to kill bacteria/ fungi that compete + decrease growth rate
3) put on growth medium with nutrients and growth hormones
4) when becomes smol plant, taken out of growth medium and planted in soil
17
Q
When is tissue culture used?
A
When plants are rare
To grow whole plants from genetically engineered plant cells
18
Q
Describe micropropagation
A
Cells are taken from developed cloned plants and subcultured (grown on another fresh culture medium) creating a large number of clones
19
Q
Arguments for artificial cloning
A
- Desirable genetic characteristics always passed onto clones
- Tissue culture allows reproduction in an season if environment is controlled
- Less space required by tissue culture than growing
- Lots of plants quickly compared to growing from seeds
- Can grow plants that have lost their ability to reproduce sexually (e.g. bananas and rare plants)
20
Q
Arguments against artificial cloning
A
- undesirable genetic characteristics are always passed on
- no genetic variability (disease could kill all)
- production costs are high bc high energy use + skilled workers so unsuitable for small scale
- contamination by microorganisms can cause complete loss
21
Q
Define embryo twinning
A
splitting an embryo to create two genetically identical embryos
22
Q
Define enucleation
A
Removal of the cell nucleus
23
Q
Define somatic cell nuclear transfer (SCNT)
A
a technique that involves transferring the nucleus from a somatic cell to an egg cell
24
Q
What two methods of artificial cloning are there in animals?
A
Artificial embryo twinning
Somatic cell nuclear transfer (SCNT)
25
Describe artificial embryo twinning
1) egg cell extracted ad fertilised in petri dish
2) left to divide at least once, forming an embryo
3) individual cells from embryo are separated and each put in a petri dish
4) each cell divides and develops normally so an embryo forms in each petri dish
5) implanted into surrogate mothers where they are born
26
Describe SCNT
1) somatic cell taken from A, the nucleus is extracted and kept
2) An oocyte (immature egg cell) is taken from B, its nucleus is removed
3) nucleus from A is put in enucleated cel from B
4) they are fused together and stimulated to divide (electrofusion) and this makes an embryo
5) implanted into surrogate mother and a clone of A is formed
27
Describe some uses of animal cloning
- research drugs (variables that come from genetic differences are removed)
- save endangered animals from extinction
- agriculture so farmers can increase no. with desirable characteristics
- animals that have been genetically modified could be cloned
- cloning embryonic stem cells to replace damaged tissue
28
Arguments for artificial animal cloning
- desirable characteristics passed on
- infertile animals can be reproduced
- increasing endangered species = biodiversity
- dont have to wait until breeding season
- new treatments for disease
29
Arguments against artificial animal cloning
- difficult, time-consuming and expensive
- undesirable characteristics passed on
- its suggested that clones may not live as long as natural offspring
- cloned human embryos = destroying life
30
Define biotechnology
the use of living organisms or parts of living organisms in industrial processes. This could be to produce food, drugs or other products
31
Four main areas of biotechnology
food, pharmaceutical drugs, enzymes and other products
32
Examples of drugs made by biotechnology
penicillin and insulin
33
Why are microorganisms used in biotechnology?
- ideal conditions are easily created
- short life cycle, grow rapidly
- can be grown on inexpensive materials
- any time of year
34
Role of microorganisms in brewing
yeast added to grain and respires anaerobically to produce ethanol and CO2 - fermentation
35
Role of microorganisms in baking
yeast makes bread rise
36
Role of microorganisms in cheese making
- used to rely on rennet which has chymosin which clots milk (used to get from calves stomachs but now can get from genetically modified yeast cells)
- lactic acid bacteria that make lactic acid= sour
37
Role of microorganisms in yogurt production
lactic acid bacteria to clot the milk and make it thicken
38
Role of microorganisms in penicillin production
When fungi are stressed, produce penicillin to stop bacteria from growing and take resources. Grown in fermenters
39
Role of microorganisms in insulin production
made by genetically modified bacteria which have had gene for human insulin production inserted into DNA. bacteria grown in industrial fermenter
40
Role of microorganisms in bioremediation
this is the process of using organisms to remove pollutants (such as oil and pesticides)
Pollutant removing bacteria that occur naturally are given extra nutrients and enhanced growing conditions.
41
Role of microorganisms in Single-cell protein (SCP)
fungus used to manufacture proteins that is used directly in food
quorn
42
Advantages of using microorganisms in food production
- faster than using animal or plant protein
- biomass produced has very high protein content
- increased/decreased according to demand
- no animal welfare issues
- no animal fat or cholesteral
- independent of seasonal variations
- not much land required
- can be grown using waste products
- easily grown in places where difficult to grow (eg malnutrition)
43
Disadvantages of using microorganisms in food production
- ideal conditions for microorganisms = also other microorganisms that could CONTAMINATE
- people dont like idea of eating food grown on waste products
- not same texture/flavour as real meat
- has to be purified
- have to be isolated from material in which they grow
- health problems (high levels of uric acid when a lot of amino acids are broken down)
44
What is a culture?
population of one type of microorganism that has been grown under controlled conditions
45
Why are fermentation vessels used?
obtain lots of the microorganism (eg for production of SCP)
| collect a lot of useful product
46
What are the two main methods of culturing microorganisms?
Batch fermentation and continuous fermentation
47
Describe batch fermentation
grown in individual batches in fermentation vessel, when one culture ends its removed and a different batch is put in, this is a closed culture
48
Describe continuous fermentation
microorganisms continuously in fermentation vessel without stopping
nutrients in waste out at constant rate
49
Conditions inside fermentation vessel
- temperature
- pH (enzymes)
- nutrients available
- oxygen availability
- concentration of product
- vessel kept sterile
50
When is continuous fermentation used?
primary metabolites
51
When is batch fermentation used?
when cells are under stress
| secondary metabolites
52
Importance of asepsis, why is contamination bad?
- competition for nutrients and space
- reduce yield
- toxic chemicals
- destroy useful microorganisms
53
Give an example of a secondary metabolite
penicillin - batch culture
54
Example of something made by continuous culture?
Insulin
55
Advantages of bioremediation
- uses natural systems
- less labour/equipment
- in situ
- few waste products
- less exposure to xclean up personnel
56
Define agar
A polysaccharide of galactose obtained from seaweed, which is used to thicken the medium into a gel
57
Define aseptic technique
sterile techniques used in culturing and manipulating organisms
58
Two types of growth mediums
broth and agar
59
Aseptic techniques
1) wash hands
2) disinfect surfaces
3) bunsen burner heat air and stop airbourne organisms for settling
4) flame bottle
5) everything flame
6) minimise time agar is open
60
Three steps of growing microorganisms on agar plates
- sterilisation
- inoculation
- incubation
61
How can you sterilise a medium?`
Autoclave, heated
62
What is inoculation?
introduction of microorganisms to sterile medium
63
What is a closed culture?
When growth takes place in a vessel thats isolated from the external environment
64
Describe a closed culture standard growth curve
1) lag phase (increases slowly bc microorganisms have to make enzymes before reproduction)
2) exponential phase (little competition and lots of food)
3) stationary phase ( death rate = birth rate)
4) decline phase (death rate greater than reproductive rate)
65
Define closed culture
a culture which has no exchange of nutrients or gases with the external environment
66
Define serial dilution
a sequence of dilutions used to reduce the concentration of a solution or suspension
67
How do microorganisms adjust to their new environment in the lag phase of a growth curve?
- taking up water
- cell growth
- switching on genes
- synthesising specific proteins (enzymes)
68
When are primary metabolites produced?
log phase, not in a closed culture
69
When are secondary metabolites produced?
stationary phase, closed culture
70
formula for number of individual
| organisms
N=N0 x 2^n
71
Define immobilised enzyme
An enzyme that is held in place and not free to diffuse through the solution
72
Advantages of immobilised enzymes
- do not mix with product so extraction costs are lower
- enzymes can be reused
- the immobilising matrix protects them from extreme conditions so high temp and pH can be used
73
Disadvantages of immobilising enzymes
expensive extra equuipment
| less active enzymes so slow
74
ways enzymes are immobilised
adsorption, covalent bonding, entrapment and membrane separation
75
Describe immobilised enzymes adsorption
bound to supporting surface by hydrophobic interactions and ionic links
bound with active site exposed (active site may be slightly distorted)
enzymes can become detached and leak
76
Describe immobilised enzymes covalent bonding
bound with covalent bonds
enzymes are bounded using a strong cross linking agent
(covalent bonding can be expensive, distort active site but less likely to leak)
77
Describe immobilised enzyme entrapment
trapped in a matrix that does not allow free movement and enzymes are unaffected and remain fully active
(substrate must diffuse in and product out)
- must be small
78
Describe immobilised enzyme membrane separation
enzymes separated from reaction mixture by a partially permeable membrane
must be small and may limit reaction rate
79
Glucose isomerase
Glucose to fructose
| produces high fructose corn syrup - diet foods
80
penicillin acylase
formation of semisynthetic
penicillins (to which some penicillinresistant
organisms are not resistant)
81
lactase
hydrolysis of lactose to glucose
and galactose
lactose free milk
82
aminoacylase
production of pure samples
of L-amino acids
synthesis of pharmaceutical and agrochemical compounds
83
glucoamylase
conversion of dextrins to
glucose
treatment of water
84
Define primary metabolite
```
Molecule made in or needed for cells normal survival and function
For example
Glucose
CO2
Ethanol
```
85
Define micropropagation
Growing large numbers of new plants from meristem tissue taken from a sample plant
86
Define tissue culture
growing new tissues, organs or plants from certain tissues cut from a sample plant
87
What are other methods of vegetative propagation that are used to produce clones?
taking cuttings, grafting (joining shoot of one plant to growing stem of another) and layering (bending a stem of a growing plant downwards so it enters the soil and grows into a new plant)
88
How do you take a cutting?
1) use a scalpel to take cutting from end of stem of parent
2) remove leaves from lower end, leaving one at tip
3) dip lower end in rooting powder, which contains hormones that induce root formation
4) plant in suitable growth medium
5) warm and moist environment - cover with plastic bag or put in propagator
6) When cutting has formed its own roots, plant it elsewhere
89
What is the process of micropropagation?
1) explants formed for pieces of cut plant
2) sterilised with bleach/alcohol
3) explant put on sterile growth medium (agar gel) with NUTRIENTS and growth hormones which encourage cells to form a callus
4) callus divided to produce more clumps of undifferentiated cells
