b6.1/2 monitoring and maintaining the environment and food security

Question 1

examples of environmental change

Answer 1

seasonal change
- average temp increase/decrease
- rainy/ hot seasons
geographic change
- land bridges sink(rising sea levels)
- habitat change
human causes change
- global warming
- intensive farming - causes deserts

Question 2

deforestation

Answer 2

removing trees
for growing crops
decreases biodiversity
growing rice increases methane levels
trees aren’t being planted as fast as the rate of deforestation

Question 3

trees cleared by burning

Answer 3

releases more CO2

Question 4

peat bogs

Answer 4

areas of west land and pest is used as fuel or compost
burning peat increase CO2 levels (as peat is a carbon sink)

Question 5

peat bogs carbon sink

Answer 5

decomposition cannot fully happen (acidic and not much O2)

Question 6

advantages of monocultures

Answer 6

• cheap labour (machines used)
• high crop yield
• easy to take care of

Question 7

disadvantages of monocultures

Answer 7

• easily affected by one disease
• soil is leached
• need fertilisers and pesticides

Question 8

bioaccumulation

Answer 8

build up of absorbed chemicals in an organism over time

Question 9

biomagnification

Answer 9

the increase in conc of these chemicals in each organism up the food chain
(organisms can’t breakdown / excrete chemicals as quick as they are absorbed)

Question 10

eutrophication

Answer 10

the process by which a body of water becomes enriched in dissolved minerals that stimulate the growth of aquatic plant life (algae)

Question 11

how eutrophication occurs

Answer 11

• sewage release / minerals from fertiliser leached into water
• algae in water have more nutrients for growth / reproduction eg nitrates
• algal bloom covers water surface
• less light in water plants cant photosynthesise and die
• algae run out of nutrients and also die
• bacteria decompose the plant / algae and respire the products using up O2 in water
• the water may become
  anoxic and all animal life dies

Question 12

global warming

Answer 12

gases trapped in Earths atmosphere eg CO2/ CH4

Question 13

CO2 levels increases due to

Answer 13

industrialisation
- more cars / factories / combustion of fossil fuels

Question 14

fluctuations of CO2 in UK because

Answer 14

• trees lose leaves - less photosynthesis - less CO2 taken in
• colder - enzymes aren’t at optimum - less photosynthesis

Question 15

implications of global warming

Answer 15

• increase sea levels
• native animals can’t survive in habitat (extinct)
• drought
• food decreases
• increases competition for land/resources

Question 16

white lemuroid possum

Answer 16

became almost extinct
cannot maintain body temp
so vulnerable to increases in temp

Question 17

little terns

Answer 17

• vulnerable to high tides / storms (increase due to global warming)
• migrate to UK and nest above high tide
• affected by flooding due to stormy seas

Question 18

coastal mangrove forests

Answer 18

• vulnerable to increase no. storms / typhoons
• these undermine the fine sediment they grow in
• seedlings can’t root
• nutrients are washed away

Question 19

biodiversity

Answer 19

the variety of all life on earth

Question 20

food security

Answer 20

when all people have access to consistent supplies of safe/ nutritious food to meet their needs for an active healthy life

Question 21

biodiversity + food security

Answer 21

biodiversity must be protected to ensure food security due to variation preventing all food being wiped out by a certain disease

Question 22

intensive farming

Answer 22

farming using machines/ chemicals to produce large yields quickly eg using fertilisers, pesticides, herbicides

Question 23

what do fertilisers/ herbicides do

Answer 23

increase mineral content of soil
removed competition

Question 24

hydroponics

Answer 24

plants grown without soil
+ production costs lower
+ minerals can be recycled
+ crops grown in areas where they normally wouldn’t
- high initial set up costs

Question 25

ethics of intensive farming

Answer 25

• close confinement ^ rise of disease spreading
• lack of movement
• nature of pens /cages
• poor transportation/ slaughtering techniques

Question 26

advantages of fish farming

Answer 26

• tank water quality can be monitored
• temp/oxygenation of water can be controlled
• the diet of fish is controlled by quality / quantity of feeding
• protected against predators (adults/young separated and separate from predators)
• pesticide are used to kill parasites
• selective breeding can improve quality

Question 27

disadvantages of fish farming

Answer 27

• spread of disease more likely as are close together
• antibiotics used to treat disease might not break down and may be eaten by humans
• waste water contains high levels of organic material which causes eutrophication
• pesticides to kill parasites can be toxic to other species nearby

Question 28

biological control

Answer 28

• controls pests without pesticides using natural predators
• most successful in controlled environments
• cause long term environmental problems