6.4 - Cloning and Biotechnology Flashcards
1
Q
define cloning
A
a way of producing offspring by asexual reproduction
2
Q
define clone
A
the offspring produced as a result of asexual reproduction
3
Q
define asexual reproduction
A
the production of genetically identical offspring from a single parent
4
Q
what is vegetative propagation?
A
where a structure develops into a fully differentiated new plant which is genetically idential to the parent
5
Q
what are examples of natural clones in plants?
A
- bulbs
- runners
- tubers
- rhizomes
6
Q
what are the uses of natural cloning in horticulture?
A
- splitting up bulbs
- removing young plants from runners
- cutting up rhizomes
- cuttings
7
Q
what are the advantages of cuttings?
A
- faster
- guarantees good characteristics
8
Q
what are the disadvantages of cuttings?
A
- lack of genetic variation
- more susceptible to disease
9
Q
what is the method for taking cuttings?
A
- use non-flowering stem
- make an slanted cut in stem
- add hormone rooting powder
- reduce leaves to 2 or 4
- keep cuttings well watered
- cover cutting with plastic bag for a few days
10
Q
what are totipotent cells?
A
a cell that can differentiate into any kind of cell
e.g. zygotes
11
Q
What are multipotent cells?
A
A cell that can form all kinds of tissues, but not whole organisms.
e.g. early embryos
12
Q
What are pluripotent cells?
A
cells that can differentiate into a limited range of cells depending on where they are found.
13
Q
Why may you use artificial cloning instead of natural cloning?
A
There is a limit to how many natural cones you can make from one plant.
14
Q
what is micropropagation?
A
Making large numbers of genetically identical offspring from a single parent plant using tissue culture techniques.
15
Q
When would micropropagation be used?
A
- selective breeding is difficult
- desired plant is rare
- Desired plant doesn’t regularly produce seeds
16
Q
What is a growth medium?
A
Something that contains nutrients. It can even be a liquid, semi solid or solid
17
Q
outline the method for micropropagation.
A
- dissect a small sample of meristem tissue in sterile conditions
- sterilise explant
- place explant in sterile culture medium
- cells form a callus
- divide callus into clumps and transfer to new culture medium with hormones
- plantlets potted into compost, and grow into small plants
- young plants planted out to grow
18
Q
what are the advantages of micro propagation?
A
- produces disease free plants
- Can produce large numbers of seedless plants
- Increase numbers of rare or endangered species.
- Rapid production of a large number of plants.
19
Q
Whatever disadvantages of micro propagation?
A
- monoculture
- expensive
- requires skilled workers
- explants are vulnerable to moulds and disease
20
Q
What type of plant tissue are natural clones produced from?
A
Meristem.
21
Q
Compare the equipment and techniques of taking cuttings with those used for micro propagation.
A
Taking cuttings uses less equipment.
Micropropagation produces more offspring
22
Q
Outline how it is possible to produce many clones from a single, original parent plant.
A
micro propagation:
- explants taken from parent plant, plantlets are then subdivided
23
Q
What are three advantages of vegetative propagation in agriculture?
A
- allows desired characteristics to be cloned
- can be done any time of year
- cheaper than micropropagation
24
Q
Where is natural cloning in animals common?
A
in invertebrates
25
What's your examples of natural cloning in animals?
- identical twins
- starfish regenerating from fragments
- hydra
- sponges
26
What are the two methods for artificial cloning of vertebrates?
- artificial embryo twinning
- somatic cell nuclear transfer
27
Outline the process of artificial embryo twinning.
1. egg fertilised by IVF
2. zygote divides by mitosis into ball of cells
3. cells are separated and allowed to divide
4. each mass of cells is placed in a surrogate uterus
28
What is artificial embryo twinning produce?
Offspring that are clones of each other.
29
What are the reasons for artificial cloning of animals?
- infertile animals can reproduce
- increase population of endangered species
- desirable genetic characteristics are always passed on
30
What are the reasons against artificial cloning of animals?
- time consuming
- expensive
- no gentetic variability so more susceptible to disease
- clones have a shorter life span
31
What does somatic cell nuclear transfer produce?
clones of the somatic cell
32
Outline the process of somatic cell nuclear transfer.
1. somatic cell taken from donor
2. unfertilised egg is enucleated
3. nucleus of somatic cell placed in enucleated ovum and fused by electrofusion
4. fertilised egg divides into an embryo
5. embryo transferred to surrogate uterus
33
What are the arguments for artificial cloning in plants?
- produce seedless plants e.g. grapes
- quicker than growing plants from seed
34
What the arguments for artificial cloning in animals?
- allows desirable characteristics to be passed on e.g. milk producing cows
35
Outline the reasons against artificial cloning implants.
- aseptic technique used in micropropgation is complec and could result in mould as more susceptible to disease
36
Outline the reasons against artificial cloning in animals.
- reduces lifespan of animals as more susceptible to health conditions
e.g. Dolly the sheep
37
What is biotechnology?
Using biological organisms in enzymes for the synthesis breakdown or transformation of materials in the service of humans.
38
What biological organisms are used in biotechnology
- Most used enzymes in the manufacturing process or the whole organism as it is more stable.
39
Why are microorganisms used in biotechnology?
- no welfare issues
- can be gentically engineered
- short life cyle + rapid growth
- simple + cheap requirements
- wide range of microorganisms can carry out different processes
40
What are examples of indirect uses of microorganisms in food production?
- baking
- brewing
- cheese making
- yoghurt makin
41
What two bacteria are used in yoghurt making?
- Streptococcus thermophilus
- Lactobacillus bulgaricus
42
what is yoghurt?
Milk that has undergone fermentation.
43
How is yoghurt made?
Two bacteria are added, which convert lactose to lactic acid. This acidity denatures the protein causing it to coagulate.
44
What is pasteurisation?
The partial sterilisation commonly using heat.
45
What does homogenised mean?
This is where fat droplets are emulsified
46
what are curds?
The solid white substance that forms when milk becomes solid.
47
What is whey?
The liquid part of the milk.
48
What enzyme coagulates the milk protein when making cheese?
rennin
49
What microorganism is used in baking?
yeast
50
How does bread rise
Carbon dioxide is produced during respiration by yeast, which is then trapped in the dough.
51
How does brewing occur?
- Barley greens that are beginning to germinate. Convert starch to maltose, which is respired by the yeast.
52
What is an example of direct use of microorganisms in food production?
mycoprotein
e.g. Quorn
53
How is mycoprotein made?
A single celled fungus is grown in a large fermentor using glucose as a food source. The microorganisms are then mixed with albumen and compressed to form a meat substitute.
54
What are the advantages of using mycoprotein instead of animal protein.
- Can be made to taste like anything
- High protein content with little fat so reduces CHD
- reproduces quickly so produces proteins faster than plants/animals
55
What are some disadvantages of using mycoprotein rather than animal protein?
- Can produce toxins if conditions aren't maintained at optimum
- Needs to be separated and processed.
- Needs carefully controlled sterile conditions.
- Often involves GM organisms - ethics?
- There is little natural flavour, s requires additives.
56
What is some advantages of using yeast to make ethanol, rather than using the chemical method?
- cheaper as lower temperatures and less energy is required
- Doesn't require oil so has a smaller carbon footprint.
57
What are some disadvantages of using yeast to make ethanol, rather than using the chemical method?
- Aseptic conditions are required.
- time consuming process.
- Product needs to be purified.
58
what are the 2 types of fermentation?
- batch fermentation
- continuous fermentation
59
What happens during batch fermentation
- Microorganisms are grown in batches in the fermentation vessel.
- Once the coach cycle is complete, the product is removed, fermenter cleaned, and a new batch of microorganisms are grown.
60
What happens during continuous fermentation
- Microorganisms are continually grown and their products harvested
- Nutrients are added and waste is removed throughout the culturing process
61
What factors must be controlled during fermentation?
- pH
- temperature
- oxygen availability
- nutrient supply
- agitation
- contamination
- waster removal
62
Why must you continuously stir the fermenter.
So the oxygen is evenly distributed.
63
Why are small fermented tanks used?
It is easier to maintain highly oxygenated conditions.
64
How is pH maintained in a fermenter?
a buffer maintains pH at 6.5
65
How is temperature maintained in a fermenter?
A water jacket keeps the temperature at 25 to 27 degrees Celsius.
66
How is the optimum oxygen maintained in a fermenter?
Sterile air is pumped into the tank.
67
How is the nutrient supply maintained in a fermenter?
Nutrients are added in circulated
68
Why is it important to continue release stir the fermenter?
So temperature, nutrients, pH, and oxygen is evenly distributed throughout
69
Why do all inlets and outlets of her industrial fermenter have filters?
To prevent contamination.
70
Outline the process of using an industrial fermenter to produce penicillin.
1. Fermenter runs for six days.
2. It is then filtered so that cells are removed.
3. Potassium compounds are added and penicillin precipitated as crystals.
4. The antibiotic is then prepared for administration
71
What are the advantages of using batch fermentation?
- Easy to meet supply and demand.
- Lower contamination risk.
- Easier to control rate of production
- less waste
72
How is penicillin produced?
- by batch culture
- Penicillin is only produced once the population has reached a certain size as it is a secondary metabolite produced under pressure.
73
Why does the fermenter tank stop after the six days?
Fungal growth and penicillin production plateaus.
74
Why does fungal grow plateau after 6 days?
There is a lack of space and nutrients which introduces competition.
75
How do bacteria reproduce?
binary fission
76
How do antibiotics work?
They interfere with the metabolism of bacteria without affecting human cells. This is called selective toxicity.
77
How is insulin made
genetic engineering
78
What is bio remediation?
The breakdown of pollutants and contaminants in soil or water using micro organisms. These can be natural organisms or genetically engineered.
79
How are microorganisms used in bioremediation?
They convert the toxic substances into less harmful ones.
80
What are aseptic techniques?
Techniques used to culture microorganisms in sterile conditions, so they aren't contaminated with unmicrobes.
81
What are some examples of aseptic techniques?
- washing hands
- no food/drink
- wearing gloves/ goggles
- working near to a lit bunsen burner
- flaming equipment
- sterilising equipment
82
Outline the process for culturing microbes.
1. Pour sterile agar into Petri dish, cover with lid, and leave to cool.
2. sterilise inoculating loop in Bunsen Burner.
3. Remove the lid and flame the rim of the culture tube.
4. Take a sample from the culture tube using the inoculating loop.
5. Flame the rim of the culture tube again before replacing the lid
6. Wipe the end of the loop gently on the surface of the agar
7. sterilise the loop
8. Tape the lid of the Petri dish.
9. Incubate upside down at 25 degrees for 24 hours.
83
Why should health and safety procedures be followed?
To minimise risk to human health by:
- minimising the risk of mutation, making a strain pathogenic
- minimising the risk of contamination from pathogenic microorganisms in the environment.
84
How would you dilute a bacterial stock?
serial dilution
85
What 3 ways can you measure the populations of microorganisms?
- direct counting
- viable counting
- turbidity
86
What is direct counting?
when you count all samples, living and dead
87
What is viable counting?
Only counting living cells by counting the colonies that grow.
88
What is turbidity?
The measure of living and dead microorganisms in solution, by taking an absorbance reading using a colometer.
89
What are the four phases of the population growth curve of a microorganism?
- lag phase
- log phase
- stationary phase
- decline phase
90
What is the lag phase?
Where the microorganism population size increases slowly as it adjusts to its new environment and gradually starts to reproduce.
91
What is the log phase?
Where the microbial population moves into exponential growth, as there's a high availability of nutrients and plenty of space.
92
Where is the stationary phase?
Where the number of microorganisms dying equals the number being reproduced by binary fission.
93
When will the stationary phase occur?
When the population reaches its maximum and it is limited by resources.
94
What is the decline phase?
Where death rate exceeds reproduction rate due to a lack of nutrients and death as a result of toxic substance buildup.
95
Outline the process of binary fission.
1. The single circular DNA molecule undergoes DNA replication.
2. Any plasmids present undergo DNA replication.
3. Parent cells divide into two cells.
4. The two daughters cells each contain a single copy of the circular DNA molecule and a variable number of plasmids.
96
What is the equation for calculating rate of cell division by binary fission?
N = N0 X 2^n
- N0 is intitial number of bacteria
- n is number of divisions
- N is final number of bacteria
