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Bio B4-B6 > B6.2 - Food Security > Flashcards

B6.2 - Food Security Flashcards

1
Q

describe 5 factors affecting levels of food security

A
  • increasing human population
  • changing diets in wealthier population
  • new pests and pathogens
  • climate change
  • sustainability and cost of agricultural inputs
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2
Q

why does an increasing human population affect food security?

A

more people = more food needed

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3
Q

how does changing diets in wealthier countries affect food security?

A
  • each person wants good food (ie. imported), or more meat (less security); meat =more energy intensive to produce than plant products
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4
Q

how does climate change affect food security?

A
  • global warming causes more droughts
  • higher desertification
  • unpredictable rain
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5
Q

positives of higher CO2 levels in the air?

A
  • they may increase crop yields (for photosynthesis)
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6
Q

how does increasing agriculture costs affect food security?

A
  • more expensive to grow food/store/distribute

- so price is too high for other people to afford

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7
Q

define food security

A

the ability of human populations to access food of sufficient quality and quantity

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8
Q

state 5 agricultural solutions to the demands of the growing human population

A
  • hydroponics
  • biological control
  • gene technology
  • fertilisers
  • pesticides
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9
Q

describe hydroponics

A
  • growing crops by replacing soil with mineral solution

- can control growth by changing temperature

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10
Q

positives of hydroponics

A
  • mineral solution can be recycled
  • plants grow quickly
  • more plants can grow n the same space (can be stacked on top of each other)
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11
Q

negatives of hydroponics

A
  • very expensive setup costs

- may not work in power outages

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12
Q

describe biological control

A
  • release a natural predator

- to kill pests where a crop is being grown

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13
Q

disadvantages of biological control?

A
  • may affect other organisms in the food web

- predator may be hard to control

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14
Q

advantages of biological control

A

is an alternative to pesticide, so an organic farming method

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15
Q

how would gene technology solve the demands of a growing human population?

A

produce them to have better yields (disease resistant, pest resistant)

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16
Q

how do herbicides and pesticides solve the demand of a growing human population?

A
  • remove animals that eat crops

- herbicides get rid of competing crops

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17
Q

negatives of pesticides and herbicides?

A
  • reduces biodiversity

- pesticides may pass up the food chain

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18
Q

difference between intensive farming and organic farming?

A

organic = avoid use of chemicals, smaller yields

intensive = main goal is maximum yield (ie. caged animals = maximum energy for mass and not movement)

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19
Q

define sustainable food production

A

producing food that can be continued for an indefinite period of time

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20
Q

how to prevent overfishing?

A
  • fish quotas (numbers + type of fish caught in that area)
  • limit mesh size (ie. bigger holes, young fish can escape - only mature, fully-sized fish caught)
  • reared in large cages in seas/rivers (protects from predators + easier to catch)
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21
Q

negatives of fishing in a cage?

A

As fish are kept so close together

  • disease spread quickly
  • disease can spread to wild population
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22
Q

what is selective breeding?

A

when humans breed certain plants or animals which have desirable characteristics (ie. may use it to increase crop yield)

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23
Q

5 step process in which selective breeding occurs?

A

1) Decide which characteristic of the species is desirable.
2) select individuals with high levels of this characteristic
3) breed from these indicates
2) select the best offspring, and breed again
3) repeat for many generations

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24
Q

disadvantages of selective breeding?

A
  • reduces gene pool (vulnerable to new pathogens)

- increased chances of inheriting a genetic disease - unforeseen physical problems (too heavy to walk)

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25
Q

how has selective breeding affected food plants? Wheat

A
  • wheat has large ears
  • generally in a way to increase crop yield
  • wheat ripens at the same time
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26
Q

define genetic engineering

A

a process which involves modifying the genome of an organism to introduce desirable characteristics

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27
Q

state the steps carried out to genetically engineer an organism

A

1) a gene is identified for the desired characteristic
2) gene is cut from the rest of DNA by restriction enzymes
3) DNA taken from bacterium (ie. plasmid/ring of DNA)
4) same restriction enzyme cuts open the plasmid
5) ligase enzymes rejoin cut out gene and plasmid ring at sticky ends
6) modified vector is placed into a bacterium
7) bacteria then reproduces through binary fission

28
Q

define the term ‘transgenic bacteria’

A

bacteria which have DNA from another organism

29
Q

when producing insulin from bacteria:

a) what gene is taken from humans
b) how is it produced?

A

a) insulin gene removed from human DNA

b) transgenic bacteria reproduce + produce insulin (a lot of it)

30
Q

what is used to see if cells incorporate foreign genes?

A
  • insert antibiotic resistant gene, if cells survive after adding antibiotics, gene has been taken up
  • insert gene markers (like glow in the dark ones)
31
Q

what is the term used to describe the organism in which the desired gene is removed from?

A

donor organism

32
Q

what is the term used to describe the organism n which the gene is inserted into?

A

host organism

33
Q

compare selective breeding to genetic engineering

A

selective b - slow process (several generations)
- may not be exact

genetic engineering - a specific gene can be targetted (more exact)
- can occur in one generation

  • both are used to change the characteristics of an organism
34
Q

explain some benefits of using gene technology in modern agriculture (4)

A
  • can have crops with desired characteristics
  • improve yields (help with population growth)
  • plants can produce their own pesticides (no need for farmer to spray)
  • crops can have vitamins (ie. golden rice) - usually hard to obtain
35
Q

explain some risks of using gene technology in modern agriculture (4)

A
  • growing with insecticides could reduce biodiversity (kill insects)
  • do not know full effects of GM on human health
    ie. allergens
  • could create ‘super weeds’ and ‘pests’, as they destroy all the other ones through making herbicides/insecticides
  • may be seen as unethical
36
Q

in terms of reproduction, why are GM crops special?

A

are infertile

  • so farmers have to keep buying new seeds every year?
  • or doesn’t affect surrounding crops and make ‘superplants’, or other farmers can unwillingly profit
37
Q

define what biotechnology is

A

the process of manipulating genes (can be using biological processes), to produce a product

38
Q

what is a biotechnological solution to the demands of the growing human population?

A

genetic modification

39
Q

give two products of genetic modification and explain how they’ve been changed

A
  • golden rice (has gene from daffodil to produce beta-carotene), the body then uses it to make vitamin A
  • (detailed: golden rice is created when a gene taken from a daffodil is placed into rice. The rice produces beta-carotene, which the body uses to make vitamin A)
  • Bt corn (has gene from bacteria which produces a poisonous protein that kills insects)
  • (Detailed: this is produced by inserting a gene into maize from the bacteria Bacillus thuringiensis. This gene codes for a protein that is poisonous to insect pests. The corn then produces the poison, killing pests that try to eat it)
40
Q

difference between genetic modification and genetic engineering?

A

genetic modification is used for plants + animals

genetic engineering is for bacteria

41
Q

how do you genetically modify an organism?

A
  • same steps as genetic engineering
  • but vector is inserted to organisms’s cell (ie. a virus)
  • so that modified DNA is copied
  • and then replicated in all the other organisms’s cells
42
Q

=-=-=-=-=-

A

=-=-=-=-

43
Q

The area available to grow crops and rear animals is limited.

How can food production be increased (4)

A
  • maximising photosynthesis.
  • using fertilisers
  • Removing competition + pests
  • planting varieties of crops that are pest resistant, or that produce a higher yield
44
Q

How does this used to increase food production:

- maximising photosynthesis.

A
  • light levels, temperature, and water supply are controlled in industrial glasshouses
45
Q

How does this used to increase food production:

  • using fertilisers
A
  • as a plant grows it removes minerals from the soil

- fertilisers help land to remain fertile

46
Q

How does this Include to increase food production:

  • Removing Competition + pests
A
  • this includes herbicides to kill weeds, insecticides to remove insects and fungicides to destroy disease-causing fungi
47
Q

Intensive farming techniques aim=

A

To produce the maximum food product yield from the minimum area of land

48
Q

Intensive farming techniques - 3

A
  • using fertilisers and pesticides to aid plant growth
  • maximising animal growth rates
  • minimising labour inputs by machinery
49
Q

Organic farming

  • methods?
  • yields/price
A

Uses more natural methods of producing crops and rearing animals, and avoids use of artificial chemicals

Yields are generally smaller, sop products may be more expensive.

50
Q

PIGS INTENSIVE FARMING

A
  • close together to keep warm and to restrict movement = more of the energy taken in from food can be used for growth
  • they are protected from predators and fed a high protein diet

Result = cheaper meat

51
Q

ORGANICALLY REARED PIGS

A
  • have space to roam = less of the energy taken in from food is used for growth

SO they are more expensive to produce

52
Q

A thing industrial greenhouses does

A
  • provides optimum conditions for photosynthesis

- for example, artificial lighting is sued to increase daylight hours

53
Q

—=-=-

A

0-=-===

54
Q

Aim of fishing quotas

A
  • to allow enough fish to survive and reproduce, to maintain their population
55
Q

How fish farming works

A
  • the fish are bed and reared in large cages in sea or rivers
56
Q

3 Fish farming advantages

A
  • fish protected from predators
  • easier to catch
  • allows wild populations to recover
57
Q

How can farmers reduce the use of fertilisers and pesticides, 4

A
  • spreading manure
  • crop rotation
  • biological control
  • gene technology
58
Q

Spreading manure why

A

Instead of using artificial fertilisers, farmers replace soil nutrients by spreading manure

59
Q

Crop rotation why

A
  • different crops take different nutrients from the soul
  • crop rotation — planting different crops each year — gives soil a chance to recover, and maximises plant growth
  • it also prevents building up a population of a particular crop pest
60
Q

3 risks of genetic engineering

A
  • eating generically engineered organisms may lead to health problems — for examples, it may introduce new allergens that may cause some people to be allergic to the organism
  • genetically engineered crops may cross-pollinate with wild plants, introducing the new gene into wild plants —> could disrupt the balance of an ecosystem
  • unethical - altering an organism’s genome is seen as science interfering with nature
61
Q

Cloning vs genetic engineering

  • genes unique?
  • genes what species?
A

Cloning | GE

  • Produces exact genetic copies | produces a unique set of genes
  • genes copied within the same species | genes transferred between species
62
Q

6 STEPS IN GENETICALLY engineering bacteria to produce insulin

A

1 - the insulin is removed from human DNA. The gene is cut from the rest of the DNA by enzymes called restriction enzymes.
2 - a loop of bacterial DNA called a plasmid is removed from the bacterial cell
3 - the loop of DNA is cut open using the same restriction enzyme that was used to cut the insulin gene from the human DNA
4 - the humans insulin gene and loop of DNA are mixed. The humans gene becomes inserted between the cut ends of the loop of DNA. The cut surfaces of the DNA are repaired using the enzyme DNA ligase.
5 - the repaired loop of DNA now carrying the human gene is then inserted into a new bacterium. The plasmid is called a vector - it carries the human gene.
6 - the bacteria are now called transgenic bacteria, because they have DNA from another organism

63
Q

Genetic engineering is not always successful, so scientists need to check that the gene has successfully transferred into the host’s genome.

One way is to add a gene for antibiotic resistance. This is the gene marker.

Explain (4)

A
  • insert an antibiotic resistance gene into the plasmid at the same time as inserting the gene coding for the desired characteristic
  • transfer the bacteria to an agar plate containing the selected antibiotic. Incubate, and allow time for the bacteria to grow.
  • any bacterial colonies present will survive because they now contain the antibiotic resistance marker gene. These bacteria will also contain the desired gene
  • samples from these colonies can then be used to build up large numbers of transgenic bacteria
64
Q

Genetically modifying a plant or animal is very similar to the prices sued to genetic engineer bacteria.

However it includes an extra stage =

A

Extra stage = the modified bacterium or virus carries the modified gene into a plant or animal cell
- plasmids, bacteria, and viruses can all be used as vectors to transfer foreign DNA into an organism

65
Q

7 STEPS FOR GENETICALY MODYFNNG AN ORGANISM (pesticide-resistance, in plant)

A

1 - The gene that controls a useful characteristic, such as pesticide resistance, is identified in a plant with natural resistance to the pesticide
2 - the gene is cut out of the pesticide-resistant plant. This is done using restriction enzymes.
3 - the DNA of a carrier or vector, e.g. a virus/bacteria, is cut open using the same restriction enzymes
4 - the useful gene is spliced into the carrier DNA, and the combined DNA is placed in a virus. The virus is injected into a plant cell. This is called insertion.
5 - The new gene is (now) inserted into the host DNA. [[ the virus has now inserted its MODIFIED gene into the host plant cell = THIS IS INSERTION]]
6 - the new gene begins to work. The host is now a transgenic organism - a genetically modified organism
7 - The GM organism is cloned, producing large numbers of identical individuals, all resistant to the pesticide

66
Q

what are sticky ends

A
  • restriction enzymes leaves a staggered cut exposing unpaired bases on each ends = sticky ends

Bio B4-B6 (9 decks)

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