6.4 Cloning and biotechnology Flashcards

1
Q

What is a clone? What is the process?

A

genetically identical copy
mitosis (asexual reproduction)

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2
Q

What are the advantages of natural cloning?

A

rapid
can predict characteristics
conditions good for parents will be good for offspring
can be carried out even when sexual reproduction isnt possible

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3
Q

What are the disadvantages of natural cloning?

A

no genetic diversity except through mutation
selection not possible
population susceptible to environmental changes

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4
Q

What is vegetative propagation?

A

reproduction through vegetative parts of the plant

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5
Q

What are runners/stolons/rhizomes?

A

runners/stolons: horizontal stems above ground
rhizomes: horizontal stems underground

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6
Q

What are suckers?

A

new stems that grow from roots. horizontal branching may die, leaving new separate stem

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7
Q

What are bulbs and corms?

A

bulbs: underground stem from which grow a series of fleshy leaf bases. Apical buds too which will grow into new plants.
corms are similar but with scaly leaves and buds

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8
Q

How about leaves?

A

clones grow on leaf margins - immature plants drop off and take root

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9
Q

What are tubers?

A

another underground stem that can grow into one or more plants

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10
Q

What is the example of natural animal cloning?

A

fertilised egg divides as normal but two daughter cells split to become two separate cells, identical twins.

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11
Q

How do you take cuttings? What are pros and cons?

A

stem cut between two nodes
cut end placed in moist soil and new roots grow
dipping end in rooting hormone helps growth

large numbers can be produced very quickly
however doing it large scale can be time consuming and it needs a lot of space

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12
Q

What is tissue culture? What is the main example?

A

growing new cells, tissues, organs or plants from certain tissues cut from a sample plant - MICROPROPAGATION

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13
Q

Outline the steps of micropropagation (7)

A
  1. material selected cut into small pieces -> explants. Must have meristematic tissue
  2. sterilisation to kill any microorganisms
  3. placed on sterile growth medium e.g. agar containing nutrients e.g. glucose, amino acids, and phosphates and hormones.
  4. callus formed, totipotent cells
  5. callus divided to produce a larger number of small clumps
  6. small clumps moved to diff growth media so that they are stimulated to grow into diff plant tissues
  7. tiny plantelets form, and these are transferred to compost/soil in a greenhouse
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14
Q

What are the advantages of artificial plant cloning? (5)

A

more rapid than growing from seed
can be carried out where sexual reproduction isnt possible or where hard to grow from seed
will display same desirable characteristics
all uniform in phenotype, so easier to harvest
using apical bud ensure new plants are disease free

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15
Q

What are the disadvantages of artificial plant cloning? (5)

A
  • labour intensive
  • expensive
  • microbial contamination
  • susceptible to same diseases
  • no genetic variation except via mutation
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16
Q

Outline embryo splitting

A
  1. Zygote created by IVF
  2. Allowed to divide to form a small ball of cells
  3. The cells are separated and allowed to continue dividing
  4. Each mass is placed into the uterus of a surrogate mother
  5. Genetically identical embryos formed
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17
Q

Outline somatic cell nuclear transfer. What is the advantage over embryo splitting?

A

can clone adults with known phenotypes
1. Egg cell obtained and enucleated
2. Somatic cell from adult to be cloned is isolated and may have nucleus removed
3. Either the complete somatic cell or just its nucleus is fused with empty egg cell by an electric shock
4. Egg cell triggered to start developing and undergo mitosis to produce a small ball of cells
5. Young embryo placed into uterus of surrogate mother

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18
Q

How is cloning used for non reproductive purposes? (2)

A

Therapeutic:
- e.g. skin grown to act as graft over burned areas
- growth of new organs for donation
- repair damage to spinal cord (this has been done in mice)
- no rejection

Research:
- research into genes that control development
- grow specific tissues/organs to test toxicity/dosage/side effects of drugs

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19
Q

What are the advantages of animal artificial cloning? (6)

A
  • animals with high yield or unusual characteristics
  • genetically identical copies of high value individuals
  • research without interference from diff genotypes
  • avoid animal testing
  • donor cells/organs
  • increase in endangered species number
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20
Q

What are the disadvantages of animal artificial cloning?

A
  • health problems
  • shorter lifespans
  • more susceptible to diseases
  • poor success rate
  • more expensive
  • ethical issues around using embryos
  • doesnt increase genetic diversity
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21
Q

Define biotechnology

A

use of living organisms or parts of living organisms in industrial processes

22
Q

Why are microorganisms used?

A
  • relatively cheap and easy to grow
  • lower temps saves fuel
  • lower pressures are safer
  • not dependent on climate
  • can be fed by-products of other industries
  • short life cycle
  • fewer ethical considerations
  • more pure
  • can be GM easily

But genetically modified mammals can also be used to produce useful proteins

23
Q

Outline yoghurt production

A
  1. Milk undergoes fermentation by Lactobacillus
  2. Lactose -> lactic acid
  3. Acidity denatures milk protein -> coagulation
  4. Other bacteria might be added as probiotics
24
Q

Outline cheese production

A
  1. Milk treated with Lactobacillus
  2. Rennet added. Rennin coagulates the casein in presence of Ca2+ ions (Kappa Casein broken down, casein insoluble and is precipitated)
  3. The curd is separated from whey by cutting, stirring and heating
  4. Curd pressed into moulds
  5. Can be given additional flavour by inoculation of Penicillium to produce ‘blue’ cheese
25
Q

Outline baking

A
  1. Mix flour, water and salt and Saccharomyces cerevisiae fungi by kneading -> dough formed
  2. Dough left for yeast to respire anaerobically. Carbon dioxide causes it to rise
  3. Cooking. Any alcohol evaporates.
26
Q

Outline alcohol beverage production

A
  • product of anaerobic respiration of yeast (Saccharomyces)
  • wine: grapes crushed, sugars used to produce ethanol
  • ale/beer: barley grains in malting. as grains germinate, starch converted to maltose, which is used to produce ethanol
27
Q

Outline SCP use

A

Fungus Fusarium
contains no animal fat or cholesterol
huge potential. some fungi can produce protein with a similar amino acid profile to animal and plant protein

28
Q

What are the advantages of using microorganisms in food production?

A
  • faster
  • biomass produced has high protein content
  • no animal welfare issues
  • no animal fat or cholesterol
  • can be easily GM to adjust amino acid content
  • independent of seasonal variations
  • not much land is required
29
Q

What are the disadvantages of using microorganisms in food production?

A
  • some people might not want to eat it
  • protein must be purified and isolated
  • can have a high proportion of nuclei acids which must be removed
  • different amino acid profile to traditional animal protein
  • care must be taken to ensure temperature doesn’t allow pathogenic organisms to reproduce
  • doesn’t have same taste or texture
30
Q

Commercial drug production uses large fermenters, where conditions are controlled. What are some of the features of a fermenter?

A

Air inlet provides oxygen in aerobic fermenters

Blades with motor to evenly distribute the microorganisms

Water jacket inlet allows circulation of water to regulate temperature

Electronic probes to measure oxygen, pH and temperature levels

Air outlets, where air bubbles mix with culture (sparging)

Inlet for addition of nutrients

31
Q

What is batch vs continuous culture?

A

CONTINUOUS:

Production of primary metabolites, continually released and can be extracted continuously, during log phase. Broth is topped up with nutrients, cells removed to prevent population from being too dense. Keeps microorganisms growing at specific growth rate.

BATCH:

Only when cells are under stress (secondary metabolites), mostly during stationary phase of growth. Culture set up with limited nutrients and allowed to ferment for specific time (closed culture). Then the fermenter is emptied and the product can be extracted.

32
Q

Why would unwanted microorganisms reduce production? Therefore what is important?

A

ASEPTIC TECHNIQUES

  • compete with cultured organisms
  • reduce yield of useful product
  • spoil product
  • produce toxic chemicals
  • destroy the cultured organisms
33
Q

Describe penicillin production

A
  1. Fermenter runs for 6-8 days. Culture filtered to remove fungal cells.
  2. Antibiotic is precipitated as crystals by addition of potassium compounds, and may be modified.
  3. Mixed with inert substances and prepared in tablet/syrup.
    Secondary metabolite -> only produced once population has reached a certain size
34
Q

Describe insulin production

A

GM an E.coli bacterium
Production of vast quantities at a low cost
Continuous culture

35
Q

What is bioremediation and its advantages?

A

Use of microorganisms to clean soil and underground water on polluted sites, since they convert toxic pollutants to less harmful substances, by using the contaminants as a food source.

Where conditions cannot be made suitable in situ, the soil may be dug up and moved to be treated ex situ.

Uses natural systems, less labour required, few waste products, less risk of exposure to clean up personnel

36
Q

How do you grow microorganisms?

A

Broth in bottles or tubes
Jelly like substance called agar, melted and poured into Petri dishes. Typical nutrient agar contains peptones, yeast extract, salts, water, glucose.

37
Q

list some aseptic techniques

A
  • disinfect work surfaces
  • wash hands
  • keep bunsen burner operating nearby to heat the air, creating a convection current and keeping the air around sterile
  • pass necks of bottles when opened over the flame to prevent microorganisms from settling on them
  • only lift the lid of Petri dishes slightly to avoid contamination
  • any glassware or equipment should also be passed through a flame before and after contact with microorganisms
  • inoculating cabinet
  • sealing incubation plates
38
Q

Growing microorganisms on agar plates involves which 3 mains steps?

A
  1. Sterilization: medium heated in autoclave, killing ALL living organisms. When medium has cooled, it is poured into Petri dishes.
  2. Incoculation can be done via streaking using inoculating loop, seeding using a pipette, or spreading using a glass spreader
  3. Incubation: do not seal completely otherwise this may cause anaerobic bacteria to rise. Placed upside down into an incubator, at a suitable temperature.
39
Q

What technique is used to investigate the rate of growth of a population of microorganisms?

A

Serial dilution, usually by factor of 10

One of the dilutions will produce a culture with which the number of colonies can be counted

To record population, you can multiply by the dilution factor, and by a number that results in the original volume.

40
Q

What is a closed culture? Describe the ‘growth curve’

A

Culture which has no exchange of nutrients or gases with the external environment

  1. Lag phase -> population small, still adjusting
  2. Log phase -> sufficient nutrients and space to grow rapidly and reproduce
  3. Stationary phase -> population growth rate declines and reproductive rate equals death rate,
  4. Decline phase due to build up of waste products and lack of nutrients. Death rate > reproductive rate, and population falls.
41
Q

What are immobilized enzymes?

A

Enzymes that are held in place and not free to diffuse through solution

42
Q

What are the advantages of immobilized enzymes?

A

Reused so less cost for new ones
Purifying cost reduced, as product not contaminated with enzyme
Protected from extreme conditions - Higher temperature allows more profit from faster yield - can be run over wider temperature range
Can be run continuously for long periods so less emptying needed

43
Q

What are the disadvantages of immobilized enzymes?

A
  • higher initial set up costs
  • fewer exposed active sites
  • leakage
  • slower process
    Method might affect shape of active site
44
Q

What are the 4 Methods to immobilize enzymes?

A
  1. Adsorption: bond to supporting surface such as clay by hydrophobic interactions and ionic links. Forces not always strong so leakage can occur.
  2. Covalent bonding: bonded to supporting surface such as clay, using strong covalent bonds, and a cross linking agent. Less likely to leak but it’s expensive and can distort active site
  3. Entrapment: trapped in matrix. Enzymes remain fully active, but only suitable where substrate and product molecules are relatively small so they can diffuse in and out.
  4. Membrane separation: separated from mixture by a partially permeable membrane. Molecules must be small enough to pass through
45
Q

Describe the use of glucose isomerase

A

Converts glucose to fructose, used to produce high fructose corn syrup. Cheaper than sucrose and widely used in diet food industry.

46
Q

Describe the use of penicillin acylase

A

Formation of semi synthetic penicillins

47
Q

Describe the use of lactase

A

Converts lactose to glucose and galactose
Lactose free milk

48
Q

Describe the use of aminoacylase

A

Produce pure samples of L amino acids by removing acyl group from nitrogen of an N-acyl-amino acid, which are then used for synthesis of many pharmaceutical compounds

49
Q

Describe use of glucoamylase

A

Converts dextrins to glucose. Used to digest sources of starch such as cassava and corn. Used to produce gasohol, an alternate fuel for motor vehicles.

50
Q

The resistance of different varieties of S tuberosum to infection by P infestans was
investigated.
* Three different clones, A, B and C, of S tuberosum were used.
* The clones were grown in adjacent fields over the same time period.
* The percentage of leaf area affected by the disease was estimated at regular intervals.

State how a clone of potatoes could be produced for this investigation

A

tissue culture/micropropagation