6.2.1 Cloning and Biotechnology COMPLETE Flashcards Preview

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1
Q

Clones

A
  • Genetically identical copies
  • Reproduces Asexually
  • Mitosis creates two identical copies of DNA which is separated to form 2 genetically identical cells
  • Clones are also formed in nature
2
Q

Examples of natural clones

A
  • Identical twins
  • Spider plant
  • Bacteria
3
Q

Advantages of Natural Cloning

A
  • Quick, reproduce rapidly
  • Don’t need a mate
  • If parent was well suited their offspring will be the same
4
Q

Disadvantages of Natural Cloning

A
  • No genetic variety
  • Equally vulnerable to disease
  • High intraspecific competition
5
Q

Vegetative cloning

A

The production of structures in an organism that can grow into new individual organisms.
Offspring contain the same genetic information as the parent therefore clones

6
Q

Examples of Vegetive Cloning

A
Root suckers 
Tubers
Bulbs 
Runners 
Rhizomes 
Corms
7
Q

Root suckers

A

New stems that grow from the roots from the meristem tissue close to the ground
e.g. Raspberry

8
Q

Tubers

A

Specialised underground stems become swollen with nutrients, forming tubers
e.g. Potato

9
Q

Bulbs

A

Condensed shoots with very short stems and fleshy leaf bases form, contain nutrients, buds at the sides develop into new bulbs
e.g. Onion

10
Q

Runners

A

Specialised stems grow along the ground from the parent plant, at the tips they form roots and shoots
e.g. Strawberries

11
Q

Rhizomes

A

A specialised horizontal stem running underground, often swollen with food. Buds develop and vertical shoots become independent plants.
e.g. Marram grass

12
Q

Corms

A

Often mistaken for bulbs, however sold rather than fleshy. It is an underground stem with scaly leaves and buds.

13
Q

Method: Cuttings

A

Produces large quantities of genetically identical plants quickly

  1. Cut stem between the leaf nodes
  2. Dip into rooting powder
  3. Place in damp soil
  4. Cover in plastic bag to prevent evaporation of water
14
Q

Method: Grafting

A

Used to ensure vigorous growth via selected rootstock. Can be used for new plants or to produce trees of different varieties

  1. Cut Scion from the desired plant
  2. Insert into the stem of rootstock, lining up vascular tissue
  3. Treat to prevent pathogens entering tissue
  4. Secure with tape
15
Q

Problems with taking cuttings and grafting

A
  • Cant produce huge numbers or cloned plants easily or quickly
  • Some plants are not suitable
  • Takes up space
  • May die
16
Q

Tissue Culture

A
  • Growing new tissues, organs or plants from certain tissues cut from a plant
  • The undifferentiated callus tissue is grown in nutrient rich medium containing plant hormones that stimulates development of the plant
17
Q

Advantages of Tissue Culture

A
  • Very large quantities of genetically identical and disease free plants can be produced from one or very few parents, quickly
  • Can be carried out at anytime of year, regardless of seasons
  • Long term storage which can easily be modified
  • Easier transport between countries as no need for quarantine
  • Produce seeds of rare plants
18
Q

Steps involved in micropropagation

A
  1. A small piece of tissue taken from shoot tip, contains meristem cells
  2. Explants are sterilised using dilute bleach
  3. Placed on a nutrient rich medium containing ingredients for photosynthesis and hormones
  4. Cells divide but do not differentiate forming a mass of undifferentiated cells called a Callus
  5. After a few weeks its removed and placed on another growing medium for shoot and root growth. (contains hormones)
  6. The plantlets are then transferred to sterile compost and acclimatised in a greenhouse.
19
Q

Why are meristem cells used in micropropagation?

A

Free from viral infections

20
Q

What is inside the medium used in micropropagation?

A

Glucose, amino acids, phosphates for photosynthesis.

Auxin and Cytokinins to stimulate mitosis

21
Q

Why does micropropagation need to be carried out in sterile conditions?

A

The medium used for growth also provides the perfect growing conditions for the growth of bacteria

22
Q

Advantages of artificial cloning Plants

A
  • Faster growing from seeds
  • Reduce genetic variation to keep only useful features
  • Some plants are unable to reproduce sexually
  • Plants will be uniform in phenotype
  • Uses apical bud which is free from infection
23
Q

Why is the meristem tissue free from viral infection?

A
  • Not enough time to reproduce as the tissue is also regenerating
  • No access to the vascular tissue
  • High levels of auxin may inactivate the virus
24
Q

Disadvantages of Artificial cloning Plants

A
  • Labour intensive
  • Expensive to set up the facilities
  • Can all fail if infected
  • Genetic uniformity means all equally susceptible to new pests, diseases and environmental change
  • No variation except mutation
25
Q

Reproductive cloning of animals:

1. Embryo Splitting

A
  1. Collect eggs from high value female
  2. Collect sperm from high value male
  3. In Vitro Fertilisation
  4. Grow to a 16 cell embryo
  5. Implant into surrogate mothers, each calf being a clone
26
Q

Reproductive cloning of animals:

2. Somatic Cell Nuclear Transfer

A
  1. A differentiated somatic cell from an adult is taken and the nucleus placed in an enucleated cell
  2. Electrofusion takes place
  3. The fertilised egg is implanted into a tied oviduct of a sheep to develop into an embryo
  4. Embryo removed and placed into a surrogate
  5. The resulting individual contains genetic information from the inserted nucleus
27
Q

Types of Reproductive cloning of animals

A
  1. Embryo splitting

2. Somatic Cell Nuclear Transfer

28
Q

Non Reproductive cloning of animals

A

Production of genetically identical cells, not used to produce organisms

29
Q

Cloning for scientific research

A

The human cell line derived from cancer cells taken from Henrietta lacks who died in the 50s, without permission
The cells are immortal a grow when the divide

30
Q

Therapeutic Cloning

A

New tissues grown as a replacement, i.e. for skin grafts one burns
Cloned cells can help repair spinal chord of a mouse.
Potential to grow new organs

31
Q

Advantages of artificial cloning in animals

A
  • High value animals can be mass cloned
  • Rare animals can be cloned
  • GM animals can be quickly reproduced
  • Repair damage to donors
  • Numbers of endangered species can be increased
32
Q

Disadvantages of artificial cloning in animals

A
  • High value animals not reproduced with welfare in mind
  • Uniformity in species makes it hard to adapt to change
  • Unclear whether cloned animals remain healthy in long term
  • Genetic diversity decreases
33
Q

Using Stem Cells in non reproductive cloning

A

Hopefully can be used to treat diseases where cells stop working, i.e. diabetes
Difficult to obtain adult stem cells
Embryonic stem cells are totipotent so could theoretically be used to grow unless cells

34
Q

Biotechnology

A

The use of living organisms or parts of living organisms in industrial processes, i.e. to produce food, drugs

35
Q

Why use Microbes

A
  • Relatively cheap
  • Rapid life cycles
  • Prokaryotes reproduce asexually
  • Proteins that are produced are easily harvested
  • No ethical issues
  • Genes are not found in pairs so its easy to genetically engineer
36
Q

Applications of biotechnology

A
  • Healthcare and medicine, produce drugs
  • Agriculture, Genetically modify plants
  • Industry, protease in washing powder
  • Food science, golden rice
37
Q

Direct Food production- Single cell protein

A

Mycoprotein/ Quorn
Grown in large fermentors, then combined with albumen and compressed into meat substitutes.
High protein and low in fat
Waste can be used to make paper

38
Q

Advantages of using microorganisms to produce human food

A
  • No animal welfare issues
  • God source of protein
  • No animal fat so lower cholesterol
  • Faster production
  • No seasonal variation in production
  • Less land required
39
Q

Disadvantages of using microorganisms to produce human food

A
  • May not want protein grown from waste
  • Microbes need to be isolated from material grown
  • Protein must be purified
  • Biomass can contain high amounts of nucleic acids
  • Doesn’t have the same texture as traditional meat
  • Flavour needs to be added
40
Q

Definition- Culture

A

A population of organisms grown under controlled conditions

Nutrients are added to provide a better medium for microbial growth

41
Q

Definition-Closed Culture

A

Isolated from the external environment so no new material added, no waste removed, no organisms removed

42
Q

Ways to Measuring Growth of a culture

A
  • Colorimeter
  • Haemocytometer
  • Viable counts
43
Q

Colorimeter

A

Measures the cloudiness/ turbidity

44
Q

Haemocytometer

A

Count the number of cells under the microscope in a known volume.
However some cels may be dead, may not be evenly distributed, hard to see

45
Q

Viable Counts

A
  • Place known volume onto nutrient agar
  • Incubate over night
  • Count the colonies
  • Use serial dilution otherwise there may be too many colonies that merge together making counting difficult
46
Q

Culture Growth- Lag phase

A
  • Bacteria are active but not reproducing
  • Adjusting to new conditions, i.e. synthesising enzymes for available nutrients
  • Length depends on the conditions
47
Q

Culture Growth- Exponential/ Log phase

A
  • Bacterial cells reproduce
  • Plenty of nutrients and space
  • Pop. doubles each generation
  • Length depends on speed of reproduction, nutrients, O2 levels
48
Q

Culture Growth- Stationary phase

A
  • Pop. levels stay the same (Death=Birth)
  • Nutrient levels fall
  • Waste (CO2) accumulates
  • Possible lack of space
  • -Reproduction eventually ceases
49
Q

Culture Growth- Decline phase

A
  • Nutrient levels low
  • Reproduction rate declines
  • Toxic waste products and metabolites
  • Death rate exceeds reproduction
  • Eventually all organisms die in a closed system
50
Q

Indirect Food Production: Cheese Making

A

Bacteria feed on lactose in the milk which changes the taste and texture
Milk is pasteurised/ homogenised and mixed with chymosin enzyme and kept till it separates
Curd and whey is separated, then strained through draining moulds .
Left pressed, dried and left to mature

51
Q

Indirect Food Production: Brewing

A

Yeast respires anaerobically to produce ethanol.
Malting involves barley germinating to produce the sugars needed by yeast
Mashing involves mixing the malt with warm water allowing enzymes to breakdown the starch and produce wort hops. (add flavour and antiseptic)
Fermentation is where wort and yeast are inoculated, temp is kept at optimum for aerobic respiration
Maturation is when beer is kept to condition

52
Q

Indirect Food Production: Baking

A

Yeast is mixed with water and sugar to respire aerobically, the co2 bubbles help bread rise
After active yeast is added to other ingredients it rises with warm conditions.
Its then knocked back, kneaded and allowed to rise further before being baked

53
Q

Indirect Food Production: Yoghurt Making

A

Uses both Lactobacillus bulgaricus and Streptococcus Thermophilus to produce yoghurt
Skimmed milk powder is added to to milk then pasteurised and homogenised, cooled at 47 degrees
Bacteria then added with a 1:1 ratio and incubated around 45 degrees.

54
Q

Advantages of using microorganisms to produce human food

A
  • No animal welfare issues
  • Good source of protein
  • Faster production
  • No seasonal variation
  • Not as much land required
55
Q

Disadvantages of using microorganisms to produce human food

A
  • Protein must be purified
  • Contamination could occur
  • Not the same texture as meat
  • Flavour needs adding
56
Q

DEFINITION- Metabolism

A

All the chemical reactions taking place in an organism

e.g. making new cells, chemicals, waste products

57
Q

Primary metabolites

A
  • Produced by an organism for growth
  • Follow the line of population size
  • Examples: Amino acids, nucleic acids, ethanol, enzymes
58
Q

Secondary metabolites

A
  • Substances produced that are not for growth but appear after the main growth period
  • Line doesn’t begin rising until stationary phase
  • Examples: penicillin, destroys bacteria that inhibit growth
59
Q

Factors to consider when scaling up

A
  • Mixing
  • distribution of O2 and nutrients
  • Overheating
  • Contamination
  • Cleaning
60
Q

Conditions that need to be controlled in Industrial Fermentors

A

Temp- increases due to respiration, needs cooling to prevent denaturing enzymes
Nutrients available- Sources of carbon, nitrogen and minerals needed
O2 conc.- Needed for aerobic respiration
pH-Enzymes are affected by extremes in pH
Product conc.- If products build up it could affect the synthesis process

61
Q

What is Batch Culture

A

Microorganism starter population is mixed with a specific quantity of sterile nutrient solution and allowed to grow for a fixed period with no nutrients added, at the end they’re removed and the tank is emptied.
Examples: penicillin, beer

62
Q

Aspects of Batch Cultures

A
  • Growth rate is slower because nutrient levels decline
  • Easy to set up and maintain
  • If contamination occurs you only lose one batch
  • Less efficient as not in operation all the time
  • Useful to produce secondary metabolites, reach stationary phase
63
Q

What is Continuous Culture

A

Sterile nutrients are added to fermentation tank and products removed at regular intervals/ continuously.
Process allows for pH levels, nutrients, and metabolic products to be kept constant

64
Q

Aspects of Continuous Culture

A
  • Growth rate is higher as nutrients are continuous;y added and it remains in the exponential phase
  • Difficult to set up, maintenance required
  • Lose huge volumes if contamination occurs
  • More efficient
  • Useful to produce primary metabolites
65
Q

Importance of Asepsis

A

If other microorganisms are present:

  • Competitions for nutrients
  • Reduced product yield
  • Spoilt product
  • Could create toxic chemicals
66
Q

Asepsis Methods

A
  • Sterilise with high temp, i.e. steam
  • Use materials with smooth easy to clean surface
  • Filter air
  • Increase pressure so air flows out
  • Wear lab clothes
67
Q

Penicillin production

A
  • Secondary metabolite so requires batch culture
  • Only produced after a certain amount of penicillium is grown
  • After exponential phase
68
Q

Production of Insulin

A
  • Genetically modified bacteria
  • Contian human insulin gene and can be grown on a large scale using continuous culture
  • Downstream processing results in a constant supply of pure human insulin
69
Q

Bioremediation

A

Use of microbes to clean soil and underground water on polluted sites
Microbes convey toxic pollutants into less harmful ones
Can be in situ or ex situ

70
Q

Advantages of Bioremediation

A
  • Less labour needed
  • Few waste products
  • Uses natural systems
  • Less risk of exposure to clean up personnel
71
Q

Immobilised enzymes

A

Enzymes can be attached onto an insoluble material so they can be reused

72
Q

Advantages of Immobilised Whole Microbes

A
  • Less expensive
  • Cells produced the enzyme
  • Cells may divide
  • Do not need to replace the enzyme
  • Useful if more than one step/enzyme involved
73
Q

Disadvantages of Immobilised Whole Microbes

A
  • Microbes will use up the substrate growing on
  • Unwanted reactions may occur, producing waste
  • More downstream processing costs
74
Q

Advantages of immobilised enzymes

A
  • Enzymes are expensive
  • Can be reused if immobilised
  • Use in continuous fermentors
  • Enzyme is protected from high temps and pH so less likely to denature
  • Product isn’t contaminated
  • Less downstream processing costs
75
Q

Disadvantages of immobilised enzymes

A
  • More setting up costs so more expensive
  • Reduced efficiency as enzymes can be less active
  • Contamination can be very costly
76
Q

Immobilising enzymes methods

A

Adsorption
Covalent bonding
Entrapment
Membrane seperation

77
Q

Adsorption

A

Ionic bonds bind enzyme to solid support such as clay, enzymes adsorbed to the surface. Helps keep them stable but more leakage due to weaker bonds

78
Q

Covalent Bonding (immobilising enzyme)

A

Enzymes are covalently bonded to the solid support, e.g. clay, using cross linking agent. Enzymes are strongly bound but may be costly

79
Q

Entrapment

A

Enzymes are trapped inside beads, such as alginate beads. The active sites aren’t affected but its difficult to entrap them.

80
Q

Membrane Seperation

A

Enzymes separated physically from the substrate mixture by a partially permeable membrane. Enzymes are therefore kept separate but the diffusion of the substrate and product from the active site can be slow

81
Q

Examples of immobilised enzymes in industry

A

Glucose Isomerase- Converts glucose to fructose for fit foods
Lactase- Converts Lactose to Glucose and Galactose for creating lactose free milk

82
Q

DEFINITION- Vegetative Propagation

A

The production of structures in an organism that can grow into new individual organisms

83
Q

DEFINITION- Tissue Culture

A

Growing new tissues, organs or plants from certain tissues cut from a plant

84
Q

DEFINITION- Explant

A

A small piece of tissue taken from a plant that contains meristematic cells

85
Q

DEFINITION- Callus

A

Mass of undifferentiated cells

86
Q

DEFINITION- Immobilisation

A

A process of confining enzyme molecule to a solid support over which a substrate is passed and converted over.