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B6.2 Flashcards

1
Q

What is food security?

A
  • ability of human populations to access affordable food of sufficient quality and quantity (safe to eat and right balance of nutrition)
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2
Q

What are the biological factors affecting food security?

A
  • increasing human population
  • changed diets in wealthier populations (meat and more varied)
  • environmental (climate) change (droughts/ expanding desserts)
  • new pests and pathogens (evolving)
  • sustainability
  • cost of agricultural inputs
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3
Q

How does change in diet affect food security?

A
  • wealthier = wider variety of food and meat (more expensive)
  • less energy and less biomass energy time you move up a mood chain = grow more food with crops than grazing animals
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4
Q

How do new pests and pathogens affect food security?

A
  • bacteria, fungi and viruses = loss of crops/ livestock and widespread famine
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5
Q

How does sustainability affect food security?

A
  • sustainability = meeting today’s population without harming environment so future generation can meet their own needs
  • unsustainably methods = permanent damage to environment/ non renewable resources = negative impact on food security
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6
Q

How does environmental change affect food security?

A
  • increased temp = affects growth patterns of crops = reduction in yield
  • rising sea levels = reduce land available for food production
  • pollution = reduces ability to grow crops
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7
Q

How does the cost of agricultural inputs affect food security?

A
  • agriculture = relies on several input = fuel (transporting food), chemicals (fertilises and pesticides), animal feed
  • high input cost (price of machinery, seeds etc.) = too expensive for ppl to start/ maintain food production = not enough ppl producing it to feed ppl =passed onto consumers = high food prices (can’t afford)
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8
Q

What are the ways of maximising food production?

A
  • max photosynthesis in plants = greenhouses that can control temp, water and light)
  • fertilisers = reduce lost minerals
  • remove competition and pests = herbicides, fungicides, insecticide, pesticides
  • grow pest resistant variety of crops/ high yield crops
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9
Q

What is the role of fungicides, pesticides, herbicides snd insecticides?

A
  • fungicides = kill fungi
  • pesticides = kill pests
  • herbicides = kill weeds
  • insecticides = kill insects
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10
Q

What is intensive farming?

A
  • using techniques to produce max yield of food from minimum area of land
  • use fertilisers and pesticides, max animal growth rates by keeping them in restricted conditions, minimise labour by using machinery
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11
Q

What is organic farming?

A
  • using natural methods (no chemicals/machinery = rely on humans) of producing crops and animals - avoid chemical use
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12
Q

Why are fertilisers used?

A
  • plants = need certain elements (N, K, P) = make proteins
  • not enough = growth and life processes affected
  • some elements are missing if used up by crops before = use fertilisers to replace/ give more of them = more crop yield
  • but can run off fields into lakes/ rivers and lakes = death of organism living in water
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13
Q

What are two forms of pest control?

A
  • pesticides

- biological control

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14
Q

How can pesticides be used for pest control?

A
  • pesticides = pest control which is sprayed onto crops = kill pests and damage them = poisonous to humans so have to keep the amount of pesticide in food below safe levels
  • several types: fungicide, insecticide, herbicides
  • some can harm wails life like needs and ladybirds = food shortage in food chain and passed up along it = accumulated in organisms lower down but larger organisms can die from it
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15
Q

What is biological control and how can it be used for pest control?

A
  • use the natural predators of the pest species to control their numbers
  • predators are bred in large numbers and released to crops to eat pests = has a longer lasting effect
  • predators may leave the eras and can eat other organisms, not the pest
  • but safer alternative as less pollution, less risk to people eating food and no passing of chem in food chain
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16
Q

What are some sustainable farming techniques?

A
  • spreading manure instead of fertilisers/ pesticides
  • crop rotations = soil can recover and prevents crop pest build up
  • pest and disease resistant varieties of crop through gene tech.
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17
Q

What is fish farming?

A
  • fish = valuable source of protein but overfishing causes less population of some species
  • international organisation = introduced fishing quotas = limit no. and type of fish caught
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18
Q

What are fish farms?

A
  • keep fish in cages / rivers = protects them from predators and makes them easier to catch while wild populations can recover
  • however a disease can spread quickly as they are close together and there is risk of them spreading to wild populations
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19
Q

What is hydroponics?

A
  • plants are not frown in soil but in nutrient solutions with all of the minerals they need
  • plants can be supported by their roots dangling into nutrient solution or they can be planted in a growth medium such as gravel, coil (brown fibres from coconuts) or perlite (naturally occurring mineral that looks like white gravel)
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20
Q

What are the advantages and disadvantages of hydroponics?

A

Advantages

  • pests and diseases can be controlled more effectively (plant diseases come from soil)
  • nutrient levels can be controlled precisely to ensure max growth
  • can deliver much height per yields
  • plants can be stacked above each other = max space

Disadvantages

  • lots of fertilisers need to be added
  • cost of setting up can be very high
  • if disease enters hydroponic system = spread quickly and cause major damage to crops
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21
Q

Where can hydroponics be used?

A
  • used to grow glasshouse tomatoes and other salad crops on a commercial scale or in areas where it’s difficult/ impossible to grow plants in soil
  • harsh climate/ barren soil
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22
Q

What is selective breeding?

A
  • process by which humans breed other animals or plants together for particular characteristics (more yield/ disease resistant)
  • also known as artificial breeding
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23
Q

Give some examples of the features we obtain in selective breeding:

A
  • Max yield of meat, milk, grain = food production is as high as possible = important for food security
  • good health and disease resistance
  • in animals = qualities like temperament, speed, fertility, good mothering skills etc.
  • in plants = qualities like attractive flowers, nice smell etc.
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24
Q

What is the basic process involved in selective breeding:

A
  • identify the desired characteristics
  • parents with high level of best / desired characteristic selected
  • bred with each other
  • best of the offspring are selected and bred
  • process is repeated over several generations to develop desired traits
25
Q

Compare the wild wheat plant with the modern wheat plant:

A
  • wild = small ears with few seeds, brittle stalks (often fall off), ears ripen at diff times, stalks grow to diff height = not good for harvesting large yields at the same time
  • modern = large ears with many seeds, stronger stalks (ears stay on easily), ears ripen at same time, stalk grow to same height = machinery can harvest and at the same height we get all seeds
26
Q

Give an example of how selective breeding can be used to combine two different desirable characteristics:

A
  • tall wheat plant = good grain yield but easily damaged by wind/rain, dwarf wheat plants can resist wind/ rain but lower grain yield
  • these 2 types of wheat = cross-bred, best resulting wheat plants were cross bred again = new variety of wheat combining the good characteristics = dwarf what plants that could resist bad weather and have a high grain yield
27
Q

What are disadvantages/ drawbacks of selective breeding?

A
  • reduces the gene pool (so less types/ numbers of alleles present) as farmers breed best animals/ plants which are closely related = inbreeding
  • inbreeding = potentially more suspectable to genetic diseases due to limited gene pool= more chances of 2 recessive diseases so seen more often
  • new disease appears = if 1 killed by a disease = all are likely to succumb as lack of variation & closely related
28
Q

What is a gene pool?

A
  • the number of different alleles (forms of a gene) in a population
29
Q

What is genetic engineering?

A
  • genetic engineering is modifying an organism’s genome by selecting genes that create desirable characteristics. This change both genotype and phenotype.
30
Q

What are genetic modified (GM) crops?

A
  • plants that have had their genes modified

- currently being grown in various parts of the world but some people strongly opposed to it

31
Q

How can crop be genetically modified to increased food production?

A
  • identify desired characteristics
  • take foreign genes from an organism that shows desired char.
  • insert into plant / animal cells at early stage of development
32
Q

Give examples of how some plants are genetically modified to increase food production:

A
  • insect resistant = prevents crops being damages = higher crop yield & farmers don’t have to use as much pesticide = other wildlife isn’t harmed
  • virus resistant = not damaged by disease cause by virus (e.g. plum trees that have been genetically modified or be resistant to plum -pox virus)
  • herbicide resistant = farmers can spray their crops to kill weeds without effecting crop itself
34
Q

What are the risks of GM crops?

A
  • unknown long term effects = negative effects can cause health problems are we are introduced to new allergens to food and cross pollination with wild plants can disrupt balance of ecosystem as pest resistant plants will be in the wild
  • might think it’s unethical as science is interfering with nature
35
Q

What is another genetic way of increasing crop yields that involves creating new plants breeds?

A
  • gather information from looking at genomes of plants to help create new breeds of crop that produce higher yields
  • scientists = researching genes that makes crops more resistant to certain biotic/abiotic factors (genes that play role in how efficiently crop uses water or give resistant to disease)
  • identifying beneficial genes in plants = we can attempt to get these genes into new crop breeds by using selective breeding techniques
36
Q

What are the benefits of GM crops?

A
  • higher crop yield (in cotton)
  • produces toxins to kill insects (corn)
  • produce key drugs like insulin by using bacteria
37
Q

What are the main 3 steps needed for genetic engineering?

A
  • identify the genes that code for desirable characteristic
  • remove the gene from the donor organism
  • insert the gene into a host organism
38
Q

What is the purpose of genetic engineering?

A
  • move genes for desirable characteristics from one organism to another so it has those characteristics too
  • organism’s genome is changed in the process
  • vector is used transfer DNA to a cell (often plasmids)
39
Q

What are plasmids?

A
  • small circular molecules of DNA that can be transferred between bacteria
40
Q

What is a vector and give some examples of it:

A
  • vectors is used to transfer and insert DNA into the cell of other organisms
  • plasmids / viruses
41
Q

What is the process of genetic engineering:

A
  • DNA you want to insert (desires char.) is cut out with a restriction
  • Plasmid is then cut open using same restriction enzyme
  • this creates sticky ends on the DNA
  • plasmid and DNA inserting are mixed together with ligase enzymes
  • ligases join the sticky ends of the two piece of DNA together
  • plasmid vectors containing new DNA are inserted into other cells (bacteria) known as hosts which can produce char.
  • last stage is to select/ identify individuals that have successfully received desired gene
42
Q

What can genetically engineered bacteria be used to produce?

A
  • they can be used to produce useful substances like hormones, antibiotics and vaccines
43
Q

What is a restriction enzyme?

A
  • they are enzymes that cut the donor DNA at specific base sequences that they recognise and leaving sticky ends
  • the same restriction enzymes are used to cut the bacterial plasmid DNA to create complementary sticky ends
44
Q

What is a ligase enzyme?

A
  • ligase enzymes join the donor gene to the plasmid by joining teh sticky ends through the formation of a bond
  • the complementary base pairings occursthrough the action of another enzyme
45
Q

What is a host?

A
  • they are what the DNA is inserted into

- uses the genes inserted to produce desired characteristics

46
Q

Why do we need to identify the individuals that have successfully recieved the desired gene?

A
  • not all host cells have been modified successfully as the vector might not have transferred properly
  • after we’ve identified them, the colonies with the desired gene can then be used to build large numbers of transgenic bacteria
47
Q

What are sticky ends?

A
  • short tails of unpaired bases that are complementary to each other)
48
Q

What are transgenic organisms?

A
  • genetically modified organisms can also be called transgenic organisms
  • they contain genes transferred from another species
49
Q

How can we check if gene has been transferred?

A
  • we use maker genes such as antibiotic resistance gene and fluorescent marker gene
50
Q

How do we use the anit-biotic resistance gene as a marker gene?

A
  • insert the marker gene into the plasmid at the same time as inserting gene for the desired characteristics
  • transfer bacteria to an agar plate with the anti - biotic
  • incubate and allow time for it to grow
  • to check the results =colonies present will have the genes
51
Q

How can we use the fluorescent marker gene?

A
  • insert marker genes into plasmid at the same time as inserting genes for desired characteristics
  • transfer bacteria to an agar plate
  • incubate and allow tie to grow
  • check results = shine UV light and those that glow have the genes
52
Q

Lack of which vitamin can cause blindness?

A
  • vitamin A, which we get from the sun but can’t = golden rice is used to provide Vitamin A to avoid this
53
Q

What is biotechnology?

A

use of biological processes or living organisms to manufacture products such as GMOs (genetically modified organisms)

54
Q

How is golden rice made and what are it’s benefits?

A
  • gene from a daffodil plant is placed into rice
  • rice produces beta- carotene which the body uses to make Vitamin A
  • combats Vitamin A deficiency diseases in places rice is heavily used (rice doesn’t have much Vitamin A) and other sources are scarce
55
Q

How is Bt corn made and what are it’s benefits?

A
  • genes from the bacteria Bacillus Thuringiensis is inserted into maize and it codes for a protein which is poisonous to insect pests
  • harmless to humans, animals and other insects
  • good thing = farmers use less pesticide
  • but there’s a danger than insects might gain resistance to the toxin and no longer be killed by it
56
Q

To genetically modify plants, what bacterium is normally used?

A

Agrobacterium tumefaciens

57
Q

What does agrobacterium tumefaciens do?

A
  • invades plant cells and inserts its genes into the plant’s DNA
  • once it has been genetically modified to include a useful genes (herbicide resistance), then it’s allowed to infect the cells of the target plant
  • bacteria will insert their genes ( including herbicide resistance) into plant’s DNA
58
Q

What is the process of make a GMO?

A
  • gene is cut out of pesticide resistance plant (identified in plant w/ natural pesticide resistance) using restriction enzyme
  • DNA of a carrier/vector (virus) is cut open by same restiction enzymes
  • useful gene is spliced into the carrier DNA and the combined DNA is placed inside a virus and the virus is injected in the plant cell = insertion
  • new gene begins work & host becomes a transgenic organism - GMO
  • GMO is cloned = produces large no. of identical individuals all resistant to the pesticide
59
Q

What are the risks of genetic engineering?

A
  • transplanted genes may get out into environment (herbicide resistance may be picked up by weeds)
  • GM crops could affect food chains or human health
  • some people are against genetic engineering = worry that change in organism’s = unforeseen problems which would get passed into future generations- e.g. long term exposure to Bt crops aren’t known yet
  • GM crops will affect no of weeds and flowers (and thus wildlife) that usually live in and around crops reducing farmland biodiversity
60
Q

What ethical issues does genetic engineering raise?

A
  • it’s wrong to genetically engineer organisms purely for human benefit (this is in animals, esp. if the animal suffers as a result)
  • people worry that we won’t stop at engineering plants and animals - may use it on children and those that can’t afford it might become ‘genetic underclass’
  • irresponsible as uncertainty about the consequences

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