Biodiversity & Food Production

Question 1

what is biodiversity?

Answer 1

the variety of all the different species of organisms on earth or within an ecosystem

Question 2

what does a great biodiversity ensure?

Answer 2

a more stable community
stability of ecosystems by reducing the dependence of one species on another for food, shelter and maintenance of physical environment

Question 3

what does the future of human species on earth rely on?

Answer 3

maintaining high biodiversity

Question 4

what human activities are reducing biodiversity?

Answer 4

waste
deforestation
global warming
land use
peat use
chemicals (that cause pollution)

Question 5

what programmes are there to reduce negative impact of humans on ecosystems & biodiversity?

Answer 5

breeding programmes for endangered species

protection & regeneration of rare habitats

reintroduction of field margins & hedgerows in agricultural areas where farmers grow one type of crop

reduction of deforestation & carbon emissions by some governments

recycling resources rather than dumping waste in landfill

Question 6

why is there an increase in the amount of waste being produced & what does this cause?

Answer 6

increase in world population & increase in standard of living
= more resources are used

causes more pollution

Question 7

where can pollution occur?

Answer 7

in water - from sewage, fertiliser or toxic chemicals
in air - from smoke (inc. CO2) & acidic gases
on land - landfill & toxic chemicals

Question 8

how does pollution reduce biodiversity?

Answer 8

kills plants & animals

Question 9

describe the process of eutrophication in 7 steps

Answer 9

1. sewage & fertilisers (have high conc. of nitrate ions) wash into lake or river
2. algae on surface grow faster (bc more mineral ions so faster ps)
3. aquatic plants are shaded by algae (no light = no ps)
4. some aquatic plants die = less ps = less O2 released into water for aerobic respiration by aquatic organisms e.g. fish
5. dead algae & plants decomposed by microorganisms
6. microorganisms aerobically respire, using up O2
7. aquatic animals (fish & invertebrates) suffocate & die & repeat step 6

Question 10

how do humans reduce amount of land available for other animals & plants?

Answer 10

building
quarrying
farming
dumping waste

Question 11

why destruct peat bogs & areas & what does this cause?

Answer 11

for garden compost
reduces area of peat habitat
= reduce variety of plant, animal & microorganism species that live there
= reduce biodiversity

Question 12

what happens when peat is burned?

Answer 12

release CO2 into atmosphere

Question 13

compost vs conservation

Answer 13

cheap compost for food production
vs
conserve peat bogs/peatland to preserve biodiversity & reduce CO2 emissions

Question 14

why has large-scale deforestation in tropical areas occurred?

Answer 14

to provide land for cattle & rice fields
to grow crops for biofuels
- both produce methane (greenhouse gas)

Question 15

what is the consequence of deforestation?

Answer 15

carbon locked as wood is released during burning - CO2 released into atmosphere

dead tree stumps are decomposed/broken down by microorganisms that respire to release CO2 into atmosphere

loss of habitat = reduce biodiversity

Question 16

what contributes to global warming?

Answer 16

increasing levels of CO2 & methane in atmosphere

Question 17

how do we know global warming is happening?

Answer 17

systematic reviews of thousands of peer reviewed publications

Question 18

describe the greenhouse effect

Answer 18

1. solar radiation reaches earth
2. some radiation is reflected from earth’s surface
3. greenhouse gases (e.g. CO2 & methane) absorb some of this energy so less radiation is reflected out of earth’s atmosphere
   some is re-radiated in all directions including to earth’s surface keeping earth warmer than it would otherwise be

do not talk about ozone layer!

Question 19

what can increase in earth’s temperature cause?

Answer 19

changes in earth’s climate - more severe & unpredictable weather patterns
rise in sea level - ice caps & glaciers melting can cause flooding
reduction in biodiversity - due to extinction
changes in animal migration patterns
changes in distribution of species
oceans hold/sequester less CO2 - less efficient CO2 ‘sinks’

Question 20

what is food security?

Answer 20

having enough food to feed a population

Question 21

what biological factors threaten food security?

Answer 21

in some countries increasing birth rate = increases population
changing diets in developed countries = scarce food resources transported around the world
new pests & pathogens
environmental changes = can cause famine e.g. if no rain
cost of agricultural inputs
conflicts impact availability of water & food

Question 22

how can efficiency of food production be improved?

Answer 22

by restricting energy transfer from food animals to environment: e.g. keep them inside

1. limiting their movement
   = lower rate of respiration to release energy for muscle contraction to move
   = less glucose used up
2. controlling temperature of their surroundings
   = lose less heat energy
   = lower rate of respiration to keep warm (exothermic)
   = less glucose used up

Question 23

how can animal growth be increased?

Answer 23

high protein food

Question 24

what are the advantages & disadvantages for intensive farming?

Answer 24

advantages: high input, high output
cheaper per serving
more efficient (less energy lost)
faster growth
less land needed per animal
more protected from weather

disadvantages: (vs opposite - free range)
ethical objections & think reduced animal welfare
higher costs of lighting, heating, antibiotics etc.
higher disease rate
more development issues in animals

Question 25

why is it important to maintain fish stocks?

Answer 25

fish stocks in ocean are declining
so breeding can continue otherwise a species may disappear completely in an area

Question 26

what 2 things help conserve fish stocks at a sustainable level?

Answer 26

controlling net size - larger holes = smaller, younger fish can escape & go onto breed
introducing fish quotas - limit number & size of fish caught

Question 27

what is mycoprotein, how is it produced & what is the benefit?

Answer 27

protein-rich food suitable for vegetarians

1. fungus fusarium is grown on glucose syrup in aerobic conditions
2. fungus aerobically respires
3. biomass is harvested & purified

fewer environmental impacts than meat while still being high in protein

Question 28

how can insulin be produced?

Answer 28

using a genetically modified bacterium that produces insulin (human protein)
when harvested & purified it can be used to treat diabetes

Question 29

what can gm crops produce?

Answer 29

more food or food with better nutritional value e.g. golden rice

Question 30

how are crops (e.g. rice) genetically modified?

Answer 30

1. new gene added to DNA of rice
2. golden rice can make vitamin a which stops diseases caused by lacking it

Question 31

what are the uses of gm crops?

Answer 31

pest resistance
drought resistance
improve nutritional value