Paper 2 - Management in Context

Question 1

State one fact from the source information that indicates New Zealand is a more economically developed country (MEDC) (1)

Answer 1

low birth rate ;
high life expectancy ;
low children per woman ;

Question 2

Describe the typical population pyramid of a MEDC (3)

Answer 2

similar shape / width for males and females ;
narrow base ;
wider in the middle ;
tall / high ;

Question 3

Explain why changing the crops grown in fields each year is a sustainable method of farming (3)

Answer 3

soil is fertile ;
soil erosion avoided ;
different crops need different nutrients / minerals / named ions ;
reduces risk of pests / disease ;
reduced use of pesticides / fertilisers ;
some crops / legumes add nutrients / minerals / mineral ions ;

Question 4

Explain how climate change may cause drought (3)

Answer 4

high / increased temperatures / global warming / (enhanced) greenhouse effect;
(high temperatures increases) evaporation / less surface water;
dry soils / land;
no / less rain / ppt;
(global warming) alters weather patterns;
more chances of extreme weather;

Question 5

Identify two pieces of evidence in the photograph that suggest drought conditions (2)

Answer 5

cracks in soil ;
no / few plants ;
no water (visible) / dry soil / land;

Question 6

State three ways the impact of drought can be managed on farms (3)

Answer 6

rainwater harvesting ;
irrigation /described ;
drought tolerant / resistant crops ;
dams and reservoirs (on farm)

Question 7

Describe the process of pollination (2)

Answer 7

the movement of pollen from an anther to a stigma ;
animal / insect / named insect pollination / wind pollination ;

Question 8

State two mineral ions in fertilisers (2)

Answer 8

nitrate ;
potassium ;
phosphate ;

Question 9

Complete the diagram (3)

Answer 9

precipitation ;
infiltration ;
ground water (flow) ;

Question 10

Suggest how farmers prevent fertilisers entering streams and rivers (3)

Answer 10

do not use on rainy / windy days;
control/use less fertiliser/follow instructions e.g. use correct quantity;
keep animals / animal waste out of / organic matter/away from rivers;
ensure plant cover / no bare soil;
plant trees / shrubs, around edges of field / near rivers / idea of a buffer at edge of field;
contour ploughing / terracing / use of bund;
direct drilling ;

Question 11

Explain why algae are producers (2)

Answer 11

they produce their own glucose;
use process of photosynthesis / trap sunlight / convert light energy;
first trophic level

Question 12

Identify the secondary consumer in this food chain (1)

Answer 12

small fish ;

Question 13

Explain the meaning of the arrows in a food chain (1)

Answer 13

(direction) of energy transfer / flow / nutrient / food flow / feeding;

Question 14

Explain the difference between a food chain and a food web (1)

Answer 14

food chain only shows one feeding relationship / food webs show alternative sources of food for organisms or consumers / food web is more than one food chain;

Question 15

“The graph shows that fishing for yellow eye mullet is a sustainable activity.” Describe one piece of evidence from the graph that supports this view (1)

Answer 15

catch are fluctuating and not decreasing;
does not exceed TACC / 30 tonnes ;
catch recovers (from a lowest point or three times) / always between 5 and 17 tonnes;
if it was not sustainable the catch would not recover ;

Question 16

Suggest one reason why the scientist recommends option three to manage this fishing area (1)

Answer 16

(lowest quota so) most likely to prevent overfishing / extinction / collapse of fish population / fish stock;

Question 17

State three management strategies that can keep a fishing area sustainable in the future (3)

Answer 17

quotas;
use smaller nets;
use larger mesh size;
limit size of boats;
limit number of boats / licences;
closed seasons;
protected areas / reserves / no fish zones;
laws / international agreements / legislation/regulations/fines/enforcement ;
monitoring fishing / patrols;

Question 18

In 2020, the sea around Stewart Island was 6°C above the mean temperature. Suggest one reason why the mass of salmon exports decreased in 2020 (1)

Answer 18

conditions no longer ideal for reproduction / growth / survival ;
reduced feeding by salmon ;
they grow better in cold water / slower in hot ;
more disease ;
stress ;
(some ) died;

Question 19

Increased ocean temperatures around New Zealand are predicted to be more frequent in the future. Explain how the enhanced greenhouse effect can cause this change (3)

Answer 19

(increased) greenhouse gases OR named greenhouse gas ;
(solar) radiation / sunlight passes through the Earth’s atmosphere ;
(some solar) radiation is lost to space;
(some solar) radiation is reflected back to the Earth’s surface ;
(solar) radiation is absorbed by the oceans;

Question 20

Suggest three possible impacts of a fish farm (3)

Answer 20

(fish / food) wastes / eutrophication;
chemical pollution from boats ;
use of pesticides;
(escaped fish) disrupt food chain / spread of disease (to wild fish stocks);
reduction of overfishing;
economic impact described;
damage to (wild) fish stocks used as food for salmon;

Question 21

State the type of mining shown in the photograph (1)

Answer 21

surface mining / open pit / opencast ;

Question 22

Suggest one risk to miners working in this mine (1)

Answer 22

falling rocks / rockfall / landslide;

Question 23

State the names of two rock types (2)

Answer 23

igneous ;
sedimentary ;
metamorphic ;

Question 24

Complete the table to show the components of soil (3)

Answer 24

micro-organisms;
air;
water ;
organic matter / humus;

Question 25

Explain why the scientist includes pots with soil in this investigation (1)

Answer 25

control / to compare the growth of plants;

Question 26

Suggest three factors the scientist should keep the same in this investigation (3)

Answer 26

volume / mass of soil / waste ;
volume of water ;
volume / size of pot ;
temperature ;
light (intensity) / daylength;
humidity;

Question 27

Write two suitable conclusions for this investigation (2)

Answer 27

plants in waste rock are shorter / stunted ;
plants in waste rock do not flower ;

Question 28

Describe how the scientist uses genetic modification to produce grass that is resistant to insect pests (3)

Answer 28

identify / find a plant that is resistant (to insects) ;
identify / extract gene(s) for resistance (to insects);
insert / introduce gene(s) into grass plants ;

Question 29

Suggest how bioremediation can be used to restore this mine (4)

Answer 29

add microbes / bacteria / fungi / microorganisms;
add organic matter ;
add soil;
plant seeds/vegetation/trees ;
introduce (grazing) animals ;

Question 30

Describe two benefits of nature reserves (2)

Answer 30

reduces human interference / stated example eg hunting ;
creates / maintains many habitats ;
increases / maintains biodiversity ;
protects (rare / endangered) species;

Question 31

Suggest reasons why some people object to a new gold mine (3)

Answer 31

(risk of) water / land / soil / air / noise / visual pollution ;
loss of, habitat / biodiversity / wildlife ;
need to relocate people ;
scare animals away ;
damage due to transport ;
loss of farm land ;

Question 32

51% of the population of Uzbekistan live in urban areas. Suggest two reasons why the population is not evenly distributed across the country (2)

Answer 32

mainly desert;
soil is infertile (most of country) / (only) fertile in east or valleys;
availability of jobs;
availability of stated resource e.g. water / food / agriculture / energy;
availability of infrastructure or named example e.g. roads;
availability of education;
availability of healthcare / sanitation or named example e.g. hospitals;
risk of natural disasters e.g. drought;

Question 33

Compare the population of males to females in the age ranges: 0–54 years and 55–100+ years (2)

Answer 33

0–54: (approximately) the same / similar / even;
55–100+: more females than males / females live longer / for both males and females from 55 to 100 population decreasing;

Question 34

The birth rate of Uzbekistan has decreased in the past 30 years. Suggest two reasons why there are fewer people aged 10–14 than people aged 25–29 (2)

Answer 34

education, use or access to or lower cost of, birth control/contraceptives;
stated or described government policy that limits or discourages number of children born e.g. anti-natalist;
idea of change healthcare;
reduction in availability of stated resource e.g. food, (clean) water;
improved education / increased opportunities for women;
disease;

Question 35

Suggest how a reduction in birth rate affects the economy of a country in the future (2)

Answer 35

reduced, economy / GDP;
less taxation / less income, (for government or country);
reduction in, work force / economically active people / less people available to work;
idea of increase in share of cost to workers or younger people for, healthcare / education / pensions / elder care;
less spending on, schools / education;

Question 36

State three ways to increase agricultural yields (3)

Answer 36

improving irrigation systems;
crop rotation;
use of fertilisers / named method e.g. manure;
use of, pesticide / insecticide / herbicide / fungicide;
mechanisation;
selective breeding;
genetic modification / GM;
controlled environments e.g. greenhouse / hydroponics / aquaculture / aeroponics;
lower price of seeds or seedlings;
reduce soil erosion / or described method of reducing soil erosion, e.g., bunds, contour ploughing, terracing, intercropping, wind breaks
use of biological control;

Question 37

Suggest how the changes in the Aral Sea have affected the economic activities of the people of Moynaq (2)

Answer 37

reduction in stated sector e.g. industry, agriculture, services;
no longer able to fish / reduced fish exports;
reduction in food or reduction in yield or food AND so people need to buy it or food prices increase;
decrease in agriculture or crop yield AND as less water available or need to pay for water or irrigation;
loss of jobs;
less tourism;
reduced work force AND due to migration;
idea of time involved or distance to travel to collect water;

Question 38

State three ways farmers can use water more efficiently (3)

Answer 38

trickle or drip irrigation;
rainwater harvesting;
use of, reservoirs / dams;
use of bunds;

Question 39

Describe how the scientist can randomly sample the Aral Sea (2)

Answer 39

use of, coordinates / grid (on a map);
(random) number generator (to identify sampling point);

Question 40

Suggest two benefits of repeat sampling (2)

Answer 40

idea of impact of different, times / seasons / weather / climate;
results can be compared / identify a trend;
identifies, anomalous results or outliers;
improves, reliability / validity;

Question 41

The student concludes that the synthetic textile is less harmful to the environment. Do you agree with the student’s conclusion? Use the information in the table to support your answer (2)

Answer 41

uses or extracts less water / uses a lot of water;
energy needed could come from non-renewable sources;
need a large quantity of energy / uses more energy;
idea that oil is, a fossil fuel / non-renewable or finite or energy comes from fossil fuels;
more CO2 / greenhouse gases, emitted;

Question 42

Explain how biosphere reserves conserve biodiversity (3)

Answer 42

prevent or limits hunting or poaching;
prevents or limits, mineral extraction / mining;
zoned / access restricted / controlled environment / protected area;
monitoring / allows for research / idea of scientists allowed in some areas;
raises awareness / education (of public);
treatment of diseases / medical support;
(eco)tourism / minimises impact of tourism;

Question 43

Define the term carrying capacity (1)

Answer 43

the maximum population or number of species that the ecosystem can sustain;

Question 44

Suggest what will happen if the Bukhara deer population continues to increase in the biosphere reserve (2)

Answer 44

shortage of food / starvation;
shortage of water;
migration;
overcrowding;
idea of deer may need to be culled or killed;
animals become weak / disease spreads;

Question 45

Describe what must be done to this disused surface mine before the Bukhara deer are introduced (3)

Answer 45

removal of waste;
fill with stated material / replace or put back overburden;
addition of (top) soil;
test (water or soil) for toxins;
bioremediation or described / improve soil / add fertiliser or organic matter;
planting (of vegetation) / food source / plant trees or plants;
provide water supply (for deer);

Question 46

Suggest the benefits and negative impacts of introducing Bukhara deer to a new location (4)

Answer 46

increases number of deer / increases population of the deer / reintroduction where deer had been extinct;
increases area or geographical range (deer found);
less risk of a whole deer population being affected by disease;
manage plant growth through grazing;
provide food source for predators;

negative effects:
may not be adapted to conditions;
displacement of other species;
changes to the food chain / not enough food;
overgrazing / damage agriculture / eat trees or crops;
may become an invasive species or non-native species;
disease (to native species or deer);
risk of hunting (in new location);

Question 47

Suggest three reasons why Uzbekistan has been slower to invest in renewable energy sources than some other countries (3)

Answer 47

large amount of, non-renewable resources / coal / oil / (natural) gas/ fossil fuels, in the country;
infrastructure for existing resources already in place;
cost (of investing in renewables);
lack of expertise or knowledge (of workers) / lack of technology or machinery;
idea of lack of natural resources to support renewables e.g. not enough sunshine hours / low wind speed;
country has other priorities e.g. drought / famine / disease / education;
stated environmental concern from use of renewables e.g. habitat loss with wind farms;
concern that renewables will not meet energy needs;
exporting existing energy resources increases GDP / oil extraction is main economic activity / idea of fossil fuels employ a lot of people;

Question 48

Explain why reducing emissions of carbon dioxide gas is important (3)

Answer 48

greenhouse gas;
contributes to global warming / (enhanced) greenhouse effect;
causes climate change;
stated effect of climate change e.g. sea level rise;

Question 49

Describe strategies to reduce electricity consumption in the domestic sector (3)

Answer 49

stated example of how to reduce use e.g. switch off lights / turn off equipment when not in use / turn water or heating
thermostat down / avoid very hot water / do not use ‘standby’;
insulation / double glazing / loft insulation / filling cavity walls;
increase number of windows to replace lighting / decrease number of windows to reduce heat loss;
open windows to replace air conditioning;
use of more efficient appliances or stated example e.g. use LED lightbulbs / heat pumps;
education / raise awareness;
stated government strategy e.g. making electricity more expensive / increased tax on electricity / limits on energy use / rationing / load shedding;

Question 50

Suggest reasons why the amount of electricity consumed by the transport sector differs between a less economically developed country (LEDC) and a more economically developed country (MEDC) (2)

Answer 50

MEDC population can afford or more people own, electric cars or EVs / MEDCs have invested more in EV infrastructure;
MEDC has a larger electric public transport system;
MEDCs, employment may not be local / people travel to work;
MEDCs have, consistent supply / more supply;
MEDCs, use more technology / technology is more advanced;

Question 51

Explain why low rainfall can increase the risk of soil erosion (2)

Answer 51

plants die;
less roots to hold or bind the soil;
less water in the soil / soil dries out;
soil (particles), become lighter / easier to blow in wind / risk of wind erosion;
less infiltration;

Question 52

Complete the table (3)

Answer 52

mineral particles: sand / silt / clay;
mineral ions: nitrate / phosphate / potassium;
organic content: (living) plants / (living) animals / microorganisms / dead remains;

Question 53

Describe ways the addition of organic matter improves the fertility of a soil (2)

Answer 53

increases water-holding capacity (of the soil);
reduces the risk of soil erosion;
increases the nutrient or mineral content of the soil / acts as a fertiliser;
improve soil structure / increase air spaces;
adds microbes / microorganisms;
increases oxygen;

Question 54

State two processes in the carbon cycle that release carbon dioxide (2)

Answer 54

respiration;
combustion;

Question 55

State two gases in clean air (2)

Answer 55

carbon dioxide / nitrogen / oxygen / water (vapour) / argon;

Question 56

State two ways the concentration of atmospheric carbon dioxide can be reduced (2)

Answer 56

carbon, capture / storage;
plant trees / afforestation / reforestation;
reduce combustion or burning of fossil fuels / increase use of renewables;

Question 57

Explain why it is important for ecosystems to be managed sustainably (3)

Answer 57

available for future generations;
prevents extinction / preserves biodiversity / prevents genetic depletion;
prevents disruption of, food webs / chains;
prevents loss of habitats or stated example of habitat destruction e.g. deforestation / soil erosion;
reduce risk of relevant natural disaster e.g. flooding or mass movement or land slides / reduce impact of drought or crop diseases;

Question 58

State what is meant by commercial agriculture (1)

Answer 58

(agriculture) for profit / making money / not for personal food production ;

Question 59

State what is meant by primary consumer (1)

Answer 59

(organism that) eats, producers / plants ;

Question 60

Suggest benefits and limitations of releasing a fungus into Somalia to control the population of Spodoptera moths (3)

Answer 60

benefits:
crop yield, increases or maintained / less plants damaged;
does not require, insecticides / pesticides / herbicides ;
economic benefit to farmer;
no water pollution / no leaching;
less risk of, pest resurgence / moths becoming resistant to fungus

limitations:
fungus may kill other, moths / non-target species / pollinators ;
disrupt food chain;
not as effective as, insecticides / pesticides / herbicides or fungus may not survive;

Question 61

A farmer notices that some individual plants in the maize crop are not affected by Spodoptera moths. Describe how these plants can be used to produce a maize crop that is resistant to Spodoptera moths (4)

Answer 61

selective breeding / artificial selection ;
collect seeds from the resistant maize ;
grow the resistant maize ;
repeat over many generations of maize ;

Question 62

A scientist investigates the population of Spodoptera moths in a 1000m2 field of maize using a random sampling technique.
Describe how the scientist:
* uses random sampling
* uses a quadrat
* records the data collected
* obtains an estimate for the population of Spodoptera moths in the field (4)

Answer 62

random sampling:
grid the field / use GPS coordinates ;
use a stated method to randomly choose quadrat sites e.g. random number generator ;

uses a quadrat:
count the number of moths in the quadrat ;

records the data collected:
use of table / tally system ;

obtains an estimate:
number of moths in a quadrat by area of field ;

Question 63

Suggest two limitations of sampling Spodoptera moths using a quadrat (2)

Answer 63

fly or move ;
could be counted more than once ;
camouflaged / difficult to identify or see ;
hide during the day / only be active at night / nocturnal ;
only be present certain times of year / may migrate ;

Question 64

Suggest one method for estimating the population of Spodoptera moths (1)

Answer 64

net / pitfall trap ;

Question 65

Suggest three reasons why the mean number of children born per woman is decreasing in many countries (3)

Answer 65

availability of contraception / family planning ;
education ;
opportunities women ;
health care / lower mortality ;
antinatalist policies ;

Question 66

In 2022, it was estimated that 2.8 million people in Somalia could not meet their daily food requirements. One strategy to prevent malnutrition is to provide school children with meals. Charities, such as the World Food Programme, provide the food for the meals. Suggest benefits and limitations of this strategy for preventing malnutrition (4)

Answer 66

benefits:
provides food or nutrients ;
easy to, administer / monitor ;
provision of free food / reference to Somalia being a LEDC ;

limitations:
not all children attend school ;
doesn’t help individuals that are not school age ;
relies on, charities / donations / expensive ;
idea of won’t solve cause of malnutrition / short term solution ;

Question 67

Suggest a suitable question that will allow a conclusion to be made (1)

Answer 67

do you live in a rural or urban area / what is your address ;

Question 68

Suggest two ways to improve the survey (2)

Answer 68

sample (men and) women / families ;
sample equal numbers of women (as men) ; randomly select the sample ;
use questions with yes/no answers / multiple choice answers ;
explain how people should answer / give instructions ;
ask more questions in the questionnaire ;
idea of sample equal numbers from rural and urban ;

Question 69

State the source of water that is accessed by wells (1)

Answer 69

groundwater ;

Question 70

Suggest two reasons why the river is dry (2)

Answer 70

drought ;
irrigation / crops / agricultural ;
livestock farming ;
industrial use ;
domestic / people use ;
construction of a dam (upstream) ;

Question 71

Describe two limitations of collecting fresh water using the method shown in the photograph (2)

Answer 71

only small volumes can be collected / only limited amount ;
well will, dry up quickly / collapse quickly ;
person may miss school / time consuming / labour intensive ;
water may contain, bacteria / diseases / pathogen / named example ;
contains soil / or is cloudy ;

Question 72

State two strategies of vector control for malaria (2)

Answer 72

removal of standing water ;
covering water / oil on water ;
killing larvae / use fish to control larvae / biological control ;
insecticide use ;
releasing sterile males ;

Question 73

State two strategies for managing the impacts of drought (2)

Answer 73

monitoring ;
emergency water supplies ;
water conservation ;
increased water supply or stated example: dams / reservoirs / wells / aquifers, water transfer / desalination / rainwater harvesting ;
international aid ;
grow drought resistant crops ;

Question 74

State three strategies for reducing soil erosion (3)

Answer 74

terracing ;
contour ploughing ;
bunds ;
wind breaks ;
plant trees / agro-forestry ;
maintain ground cover ;
add organic manure ;
mixed cropping / intercropping ;
crop rotation ;
improved irrigation e.g. trickle drip ;

Question 75

State the name of the type of mining shown in the photograph (1)

Answer 75

deep mining / shaft mining / subsurface mining ;

Question 76

State three factors that the company must consider before deciding to extract the uranium (3)

Answer 76

size of deposits ;
accessibility of the deposits / depth of deposit ;
stated environmental impact of mine: e.g., waste disposal / transport impact / habitat destruction / loss of biodiversity / ease of restoration ;
stated human impact / health implications e.g. radiation risk / cancer ;
cost (extraction) ;
value of the uranium / profitability ;
government licences ;
availability of, labour / machinery ;
public opposition;

Question 77

Suggest how the mine will affect people living in a nearby village (4)

Answer 77

water pollution ;
noise / visual / air / soil pollution from stated source ;
fear over, radioactive sources / contamination ;
village may need to be relocated ;
employment opportunities ;
improvement in local economy ;
improvement in national economy / increased tax revenue for government ;
improvement in infrastructure / healthcare / schools ;
loss of recreational areas for village ;

Question 78

Describe two strategies to restore the landscape (4)

Answer 78

fill the hole with stated material e.g. mine waste / rock / spoil ;
cover with topsoil ;
soil improvement ;
stated example e.g. add fertiliser / add (treated) sewage or manure ;
bioremediation ;
use of bacteria / microbes ;
plant grasses ;
plant shrubs or trees ;
safe disposal of (remaining) mining waste ;
restore natural habitats / create nature reserve ;

Question 79

Suggest three reasons why Somalia exports all of its uranium and does not use it to generate electricity (3)

Answer 79

no current nuclear power plant ;
lack of money (to build or run or maintain nuclear power station) ;
lack of expertise ;
other alternatives are more available / Somalia has oil reserves ;
other alternatives are cheaper ;
people are opposed to nuclear energy ;
(exporting uranium) makes money ;
idea of issue of storage of nuclear waste ;

Question 80

State why this solar power station cannot generate electricity 24‑hours per day (1)

Answer 80

needs sunlight ;

Question 81

Suggest benefits of this solar power station for the people in Mogadishu (3)

Answer 81

more access to electricity / more electricity available;
reduces the costs of electricity ;
reduces the dependence on fossil fuels / non-renewable resources ;
reduces air pollution or stated example: smog / carbon emissions / climate change / global warming / no greenhouse gases ;
idea that it helps raise people out of poverty ;
employment opportunities, at power station / in local industries ;
improved economy or stated example e.g. improved infrastructure ;

Question 82

State three intensive agricultural practices (3)

Answer 82

mechanisation;
(synthetic) fertiliser;
insecticide / pesticide / biological control;
weed control / herbicide / fungi control / fungicide;
planting multiple crops per year / intercropping;
(increased use of) irrigation;
reducing frequency of fallow years;
large numbers of animals on limited land;
crop rotation;
controlled environments, greenhouses / hydroponics;
irrigation;
monoculture;

Question 83

State the benefits and negative impacts of intensive agricultural practices (4)

Answer 83

benefits:
idea of increased efficiency;
increase yields;
increased profits;
less workforce needed;
cheaper food;
meets needs of current generation;

negative impacts:
deforestation;
habitat loss;
disruption of food chains;
loss of biodiversity;
genetic depletion;
large amounts of (animal) waste;
high use of, energy / resources / water;
not sustainable;
salinisation / increased salinity;
loss of soil, fertility / nutrients / minerals / organic content;
soil compaction / erosion / leaching / eutrophication;

Question 84

Suggest one reason why the soil samples are passed through a 2mm sieve (1)

Answer 84

to remove stones;
so they contain similar-sized particles of soil;

Question 85

Suggest one reason why the water is removed (1)

Answer 85

so (ions in) water is not measured;
so each sample is comparable;

Question 86

Suggest one reason why all seven soil samples are put into the same large container before being analysed (1)

Answer 86

to get representative data for the whole field;
to get a large enough sample to analyse;

Question 87

Add three other components of soil to the list (3)

Answer 87

air;
water;
organic / dead remains;
microorganisms / named microorganism ;
plant / animal;

Question 88

Suggest benefits of HS2 (a railway track for high-speed trains) to people living in the UK (2)

Answer 88

reduced carbon emissions;
north to south of country is linked;
improves connection between cities;
allows faster transport of, goods / people;
increased tourism opportunities;
improved economy;
reduces, traffic / vehicles / cars / lorries / trucks / air travel;

Question 89

Suggest two impacts of building a large number of houses near the HS2 (a railway track for high-speed trains) stations. Give a reason for each impact (4)

Answer 89

loss of biodiversity;
habitat destroyed / deforestation;
increased urbanisation;
more employment opportunities / economic growth;
noise pollution (from construction);
due to machinery;
as more hard surfaces;
increased run-off / flooding;
loss of farmland;

Question 90

Explain why emitting less carbon is important (3)

Answer 90

carbon dioxide is a greenhouse gas;
contribute to global warming / climate change / (enhanced) greenhouse effect;
stated effect of climate change, e.g. sea level rise / flooding;
helps to meet carbon neutral target;

Question 91

Explain how trees help to reduce carbon emissions (2)

Answer 91

(trees) absorb carbon dioxide;
store the carbon;
due to photosynthesis;
6CO2 + 6H2O → C6H12O6 + 6O2 /
carbon dioxide + water → glucose + oxygen;

Question 92

Suggest why the green corridor must be made before construction of the track begins (1)

Answer 92

animals can escape (the building work);
to maintain animal migration routes;
to link breeding grounds;
to link populations;

Question 93

Japanese knotweed is an invasive plant species. This means it is not native to the UK and does not grow naturally in the UK. Suggest one reason why Japanese knotweed is removed from the green corridor (1)

Answer 93

idea of competition (with native species);

Question 94

Japanese knotweed is an invasive plant species. This means it is not native to the UK and does not grow naturally in the UK. Suggest one reason why vehicles in an area with Japanese knotweed must be washed before leaving the area (1)

Answer 94

to reduce the risk of spread (of the knotweed);

Question 95

Suggest one reason why some people are concerned that the construction of houses in the UK may cause some Bechstein bats to die from starvation (1)

Answer 95

reduction in food ;
disruption of food chain;
migration of prey;
harder to catch prey;

Question 96

Suggest a reason why the survey should be carried out between sunset and sunrise (1)

Answer 96

bats are nocturnal / only active at night;

Question 97

Suggest a reason why this type of survey can result in an overestimate of the bat population (1)

Answer 97

same bat could be counted more than once;
public are not experts (so may count other species);

Question 98

Suggest four benefits of asking local people to complete bat population surveys (4)

Answer 98

local knowledge of, where bats are / when bats active;
many people can help;
low cost;
large amount of data can be collected;
data can be collected quickly;
raises awareness of the animal;

Question 99

Suggest a reason why climate change could shorten the length of time that Bechstein bats hibernate (1)

Answer 99

warmer temperatures;

Question 100

Suggest the short-term impact of a reduction in Bechstein bat numbers on the tawny owl bird. Give a reason for your answer (1)

Answer 100

numbers decrease AND they have less food to eat;

Question 101

State two ways pollination can occur (2)

Answer 101

animals;
wind;
insects;
birds;
self-pollination;

Question 102

Explain what is meant by bioaccumulation (2)

Answer 102

(toxic substance) is absorbed;
(absorbed) faster than it is lost (from an organism) / not excreted (fast enough) ;

Question 103

Suggest two reasons why a country is a net importer of energy (2)

Answer 103

increasing demand / demand exceeds supply;
increasing population;
availability of, own natural reserves / named resource;
accessibility of, natural reserves / named reserve;
cost too high to extract own natural reserves / cheaper to buy it (than produce);

Question 104

Suggest one limitation for a country being a net importer of energy (1)

Answer 104

reliant on other countries;
cannot set own energy policies;
cost of imports;
possible power shortages / disruption to supply;

Question 105

State why a pilot questionnaire is carried out before the main questionnaire (1)

Answer 105

test whether questions are, suitable / clear;
test whether sampling methods are suitable;
identify any problems with the questions;
check that answers can be easily analysed;

Question 106

Suggest why fracking might go ahead even if local people are against the idea (1)

Answer 106

shortage of, gas / oil;
high demand / current oil and gas supplies don’t meet demand;

Question 107

Suggest one reason why the UK government decided to stop fracking in November 2019 (1)

Answer 107

too many earthquakes;
probability / magnitude, of earthquakes cannot be predicted;
public opposition / public feel fracking is not safe;

Question 108

State three ways to prepare for a natural hazard to help prevent deaths (3)

Answer 108

evacuation plans;
drills;
emergency supplies;
emergency rescue teams;
early warning systems / monitoring;
education of public;
emergency shelters;
medical teams;
earthquake resistant buildings;

Question 109

State three causes of flooding (3)

Answer 109

heavy rainfall;
low-lying land;
saturated / compacted, soil;
deforestation / removal of vegetation;
urbanisation;
storm surges / tsunamis;

Question 110

Explain how flooding can benefit farmers (2)

Answer 110

deposition of silt / silting;
improves fertility of soil;

Question 111

Explain why it is not possible to grow crops at Halley scientific research centre in Antarctica (4)

Answer 111

lack of sunlight;
(extreme) cold;
no, rain / precipitation;
water trapped as ice / no available water;
prevents photosynthesis;
built on ice / no soil / ground frozen;

Question 112

Suggest reasons why Halley scientific research station in Antarctica is built on giant metal skis, with legs that can be adjusted (4)

Answer 112

easily moved;
height above ice can be increased;
legs can be removed / stops it getting buried / stops legs getting stuck / reduces land pollution;
increases surface area / stops sinking;
idea of durability or strength of metal;

Question 113

The accommodation is built using insulating material that is very good at reducing heat loss. Suggest two reasons why this is important at Halley scientific research centre in Antarctica (2)

Answer 113

cold temperatures / keep people warm;
reducing energy use or energy resources / increased efficiency ;
all energy resources must be brought in;
(in cold) machinery stops working;

Question 114

Suggest reasons why it is important to minimise the quantity of waste produced at Halley scientific research centre in Antarctica (2)

Answer 114

costly to remove;
difficult to store / reduces quantity to store;
difficult to transport;
less energy needed to remove the waste;
prevents, visual /smell / water / atmospheric pollution;

Question 115

Suggest why sewage and food waste are not removed from Antarctica (1)

Answer 115

large amounts / difficult to transport / long distance to transport;
idea that transportation increases risk of disease or water pollution;
smell;

Question 116

Suggest one reason why pressure builds up in the bioreactor (1)

Answer 116

carbon dioxide / gas (is produced);

Question 117

State three abiotic components in an ecosystem (3)

Answer 117

temperature;
humidity / water;
oxygen;
salinity;
light;
pH;

Question 118

Suggest one environmental impact of burning waste sewage sludge (1)

Answer 118

carbon dioxide / greenhouse gases, released;
global warming / climate change;
smell;

Question 119

In many countries, waste sewage sludge is spread onto fields. Suggest one benefit of this practice to farmers (1)

Answer 119

increases soil fertility / adds, nutrients or organic matter, to soil;
(organic) fertiliser;
increases crop yield;

Question 120

State two renewable energy resources (2)

Answer 120

biofuels;
geothermal;
hydro(electric) / HEP;
tidal;
wave;
solar;
wind;

Question 121

Suggest reasons why rats needed to be removed from South Georgia (2)

Answer 121

competition / outcompeting (native species);
no natural predator;
predators (to native species) / endanger populations (of native species);
idea of ease of predation, e.g. eat nesting birds as no groundcover;

Question 122

A total of 300 tonnes of poisoned rat food were dropped on the island from the air over five years as part of the removal programme. Suggest why some scientists were concerned about this method of rat removal (1)

Answer 122

can kill non-target species / other species eat rat poison;
poison can enter water sources;

Question 123

Strategies are used to keep South Georgia Island rat free. They include:
* keeping large tourist boats offshore
* moving people to the island in smaller boats.
Suggest how these strategies help to keep the island rat free (1)

Answer 123

can’t hide;
easier to see;
easier to remove;

Question 124

After the poisoned rat food was dropped, two methods were used to find out if all the rats
were removed.
method 1: Three dogs were walked 2500km around the island. The dogs were trained
to identify rats by their smell.
method 2: Thousands of chew sticks were installed around the island to detect signs of
rat teeth-marks.
Suggest limitations for each method (3)

Answer 124

dogs method 1:
only walked part of the island / 3 dogs can’t cover all island;
dogs might miss a rat / can’t smell them over a long distance / rats move around;
dogs can only work for a limited period of time;
cold weather conditions for dogs;

chew sticks method 2:
costly, as thousands needed;
time consuming / need to be inspected for chew marks
other animals might chew them / difficult to interpret type of chew marks;
rats may not use chew stick / chew stick not in area where rats are;
same rat may have chewed on different sticks;
chew sticks might get buried (by snow);

Question 125

New Zealand consists of about 600 islands. It has a total area of 268021km2 and a population
of approximately five million people. New Zealand plans to remove all their rats by 2050.
Suggest reasons why the removal programme will be more difficult in New Zealand than on
South Georgia (3)

Answer 125

larger area of land / more islands;
people live there;
trees / ground cover (for rats to hide);
people may protest / concern over harm to people;
more food sources;
more people or ships arriving or leaving;

Question 126

State two strategies to treat water that contains bacteria to make it safe to drink (2)

Answer 126

boiling;
chlorination;

Question 127

Explain what is meant by unsustainable fishing (2)

Answer 127

fished at a greater rate than population can recover;
eventually stocks run out / fish unavailable for future generations;
young fish are caught / reproduction cannot occur;

Question 128

Suggest reasons why there is a large trade in illegal fishing of the Patagonian toothfish (3)

Answer 128

difficult to patrol or monitor (fishing boats as ocean is large);
worth a lot of money;
so fishermen do not want to throw back;
easily caught in nets / easily caught as bycatch;

Question 129

State three ways the harvesting of marine species in the Southern Ocean can be managed (3)

Answer 129

use smaller nets;
use larger mesh size;
limit size of boats;
quotas / limit number of boats / licences;
closed seasons;
protected areas / reserves / no fish zones;
laws / international agreements / legislation;
monitoring / patrols;
fines / enforcement;

Question 130

Suggest reasons why climate change could reduce the size of the krill population (2)

Answer 130

water too warm;
change in ocean circulation;
change in predators;
change in availability of, food / phytoplankton / nutrients;

Question 131

Suggest why thin slices of an ice core are individually analysed rather than the whole length of the ice core (1)

Answer 131

individual years can be identified;
each slice represents a different time period;

Question 132

Suggest how major volcanic eruptions are used to determine the age of a slice of an ice core (1)

Answer 132

idea that we know when the volcano occurred, so we know the age of the layer which contains ash;
chemical evidence of the volcanic eruption (in the ice);

Question 133

State the names of two greenhouse gases (2)

Answer 133

carbon dioxide;
methane;
water (vapour);

Question 134

Explain why climate change is causing sea levels to rise (3)

Answer 134

melting, ice / ice sheets / glaciers / permafrost;
water in the seas is warming (due to atmospheric warming);
volume of water in seas or oceans expands;

Question 135

Explain why ozone depletion is a concern (3)

Answer 135

higher levels of, UV / ultraviolet radiation (reach Earth);
skin cancer;
cataracts;
damage to vegetation;

Question 136

Tourists travel to Antarctica by ship. They visit for one to three hours each day in groups
of less than 100. They must be supervised by experts on Antarctic wildlife. Suggest how this strategy limits the impact of tourism on Antarctic wildlife (2)

Answer 136

prevents tourists feeding animals / touching animals / making noises / dropping litter / less waste;
prevents disturbance of, breeding / feeding;
educate the tourists about Antarctica;

Question 137

Explain how a double-hulled ship can reduce the risk of an oil spill (2)

Answer 137

outer / first, hull damaged;
inner / second, hull prevents the oil entering the ocean;

Question 138

State one strategy for dealing with an oil spill (1)

Answer 138

boom / detergent (sprays) / skimmers

Question 139

Describe the impacts of an oil spill on marine mammals (3)

Answer 139

oil coats fur / skin;
destroys insulating ability of fur;
leads to hypothermia;
oil ingested / taken in during feeding or when cleaning;
toxic;
bioaccumulation;
oil inhaled / suffocation;
oil gets in eyes;
reduction in food;

Question 140

Suggest three reasons why young people live in urban areas (3)

Answer 140

better jobs;
higher wages;
education opportunities;
better infrastructure;
improved healthcare;
internet access / communication network;

Question 141

Suggest reasons why travelling long distances to collect clean water is one of the causes of poverty (3)

Answer 141

takes up time;
can’t, have regular a job / do work;
can’t attend school;
travel can be dangerous / might get injured;

Question 142

Cholera is a water-related disease. Explain why people become infected with cholera (2)

Answer 142

consuming, contaminated water or food / untreated water;
(contaminated with) sewage / containing (cholera) bacteria;

Question 143

State two strategies to control cholera (2)

Answer 143

boiling;
chlorination;

Question 144

State two strategies for improving water quality (2)

Answer 144

boiling;
chlorination;
improving sanitation;
treatment of sewage;
education campaigns / awareness;
stated example of legislation e.g. on pollution control / water quality;

Question 145

Suggest limitations of using this map to predict the risk of becoming infected with malaria (2)

Answer 145

data is only for one year;
data is not for current year;
risk may vary month to month / depend on season;
risk may be different in within each area;
does not say when mosquitos are active;
doesn’t include standing water / breeding grounds;
methods to reduce risk aren’t known e.g. vaccination / use of nets;
doesn’t show settlement locations e.g. which area people are in;
stated example of a limitation of data intervals e.g. 5–99 is broad;

Question 146

Two strategies to control malaria are:
* the use of antimalarial drugs
* the use of mosquito nets.
Compare these strategies as methods of controlling malaria in Zimbabwe (5)

Answer 146

antimalarial drugs:
benefits:
work quickly;
stop parasite multiplying / kill parasite;
idea of protected all day / reduces number of people (getting) infected;
limitations:
expensive;
short-term fix;
not guaranteed;
side-effects;
still get bitten by mosquitos;
must be taken in advance;
lack of access to medical / limited availability for some countries;

mosquito nets:
benefits
controls vector / stops mosquito bites;
readily available;
easy to use;
can be used on door or windows;
limitations:
have to stay under them / mosquitoes can enter during entry or exit
idea of not practical to use during day
get damaged easily

Question 147

Plan 1
* Visit each site, A–D, on one day in January.
* Collect samples of water and fish.
Plan 2
* Visit each site, A–D, on one day in January, one day in March and one day in May.
* Collect samples of water and fish on each day.
The scientist uses Plan 2 to investigate the concentration of mercury found in the water and
the fish. Describe the advantages of using Plan 2 rather than Plan 1 (3)

Answer 147

greater number of months / sampling repeated / more data;
more representative of the year / concentrations may vary each month / variables change;
allows for anomalies to be identified;

Question 148

State three sources of fresh water for people (3)

Answer 148

reservoirs;
lakes;
aquifers;
wells;
rivers;
desalination plants;

Question 149

Suggest three problems of using hydroelectric power (3)

Answer 149

flood large areas / loss of land;
forced relocation of people;
restrict (downstream), water flow / irrigation;
silting;
risk of dam bursting;
require, maintenance / expertise / skilled workers;
affects migration;
requires rainfall or water source / effected by drought;
requires specific terrain e.g. mountainous / valley;

Question 150

Describe two ways that the extraction of coal pollutes the environment (2)

Answer 150

noise pollution AND from, machinery / transportation / vehicles;
noise pollution AND changing animal behaviour;
visual / water, pollution AND from, overburden / spoil;
visual / water pollution AND from, waste / chemicals;

Question 151

Describe how acid rain is formed (3)

Answer 151

combustion or burning of fossil fuels;
formation sulfur dioxide or SO2 / sulfur reacts with oxygen / S + O2 → SO2;
nitrogen in the air reacts in vehicle engines;
formation oxides of nitrogen or NOx;
any two from:
(their SO2 or NOx) gas reacts / mixes / disolves with water or H2O;
to form sulfuric acid / H2SO4 / nitric acid / HNO3;

Question 152

State two negative impacts of acid rain (2)

Answer 152

acidification of bodies of water;
reduce fish populations;
reduce crop yield / reduce foliage;
acidification of soil;
damage to buildings;

Question 153

Zimbabwe has:
* wood waste from its timber industry
* an average of 8.2 hours of sunshine per day.
Suggest how Zimbabwe could use these renewable resources to increase its electricity
supply (3)

Answer 153

wood waste:
used as (bio)fuel / burnt;
generating electricity described e.g. heat used to turn water into steam and turn turbine and turn generator;

sunlight:
used by, solar cells / panels / solar power;
energy produced can be stored in batteries;

Question 154

Suggest reasons why Zimbabwe has not developed their renewable resources of energy (3)

Answer 154

economic challenges;
abundance of other resources e.g. coal;
lack of, expertise / workforce;
lack of, technology / machinery / materials to build equipment or structures;
lack of space / no places to install;
lack of political will / public opposition;

Question 155

State three techniques used to increase agricultural yield (3)

Answer 155

fertilisers;
crop rotation;
improved irrigation / named method e.g. trickle drip;
insect control / insecticide / biological control;
weed control / herbicide;
fungi control / fungicide;
mechanisation;
selective breeding;
genetically modified organisms / GM;
controlled environments / greenhouses / hydroponics;

Question 156

Suggest why soil erosion is more common in a less economically developed country (LEDC) such as Zimbabwe (3)

Answer 156

less money available for, equipment / fertilisers;
less, education / understanding of soil science;
less-developed irrigation systems;
more pressure to monoculture;
more land clearance;
many people or large areas of land, involved in agriculture;

Question 157

Explain why a lack of oxygen leads to the death of aquatic organisms (1)

Answer 157

idea that organisms are unable to respire;

Question 158

State what is meant by cash crop (1)

Answer 158

produced to, be sold / make a profit / not used or eaten by the farm

Question 159

Describe a systematic sampling method for selecting farmers to be surveyed by
questionnaire (1)

Answer 159

valid description of a method of systematic sampling, e.g. every nth farm;

Question 160

Suggest three reasons why the number of questionnaires returned was fewer than the
number of farmers selected for survey (3)

Answer 160

did not grow crops / were not arable farmers;
declined the survey / did not want to do it;
unavailable / too busy working / lack of time;
unwell / had died;
did not speak the same language (as the questionnaire);
illiterate / could not read;
questionnaires lost (in post);
stopped being farmers;

Question 161

Suggest two reasons why only a small number of people live in rural areas (2)

Answer 161

not many jobs / risk of being unemployed;
only agriculture as available work / mechanisation of agricultural;
migration;
lack of services or infrastructure / fewer stated services e.g. medical care / education / communications;

Question 162

Give two reasons why most farmers near Copenhagen do not use irrigation methods to grow crops (2)

Answer 162

many wet days;
similar rainfall every month;
no dry season / rains all year;
suitable data quoted e.g. 70 mm every month, every month has between 7−89 mm, minimum of 11 wet days each month

Question 163

Describe the environmental impacts of mismanagement of irrigation (3)

Answer 163

waterlogging / flooding;
low oxygen or air in soil;
reduced crop yield;
salinisation;
loss of, fertility / fertiliser;
leaching (of nutrients);
leading to eutrophication;
AVP; e.g. soil erosion / increased surface run-off

Question 164

State the names of the two main ions present in fertilisers (2)

Answer 164

nitrate;
potassium;
phosphate;

Question 165

Suggest two reasons why nitrous oxide emissions from farming in Denmark will not reach zero tonnes in the future (2)

Answer 165

farming always needed;
some fertilisers (always) needed;
NOx released from farm machinery;
there will always be N compounds to break down / not possible to stop bacterial activity in the soil;

Question 166

Suggest reasons why the population of Denmark may be impacted by climate change (4)

Answer 166

sea level rise;
flooding;
drought
loss of farmland;
loss of habitat / loss of biodiversity;
reduction in crop yield / new crops could be grown;
displacement of people / forced migration / loose their homes;
increased land prices;
transport routes cut / damage to infrastructure;
salinisation of water supplies;
extreme weather / changed weather patterns;
impact on energy costs;

Question 167

State three components of a fertile soil (3)

Answer 167

mineral ions;
air;
water;
microorganisms / bacteria / fungi;
organic matter;

Question 168

Describe one method the scientists can use to produce new varieties of apple trees (3)

Answer 168

genetic, engineering / manipulation;
identify the gene for high yield (from a high-yielding tree);
extract the gene (from the high-yielding tree);
insert the gene (into a stock tree);

selective breeding;
select two suitable parent trees (e.g. high-yielding);
cross-breed the parents;
select the most promising offspring;

Question 169

State what is meant by the term ecosystem (1)

Answer 169

all the living or biotic AND non-living or abiotic components (in an area);

Question 170

Describe how timber extraction can be done to maintain biodiversity (2)

Answer 170

selective logging / sustainable harvesting;
species, not made extinct / can recover;
replant native species;
protected zones in the forest;

Question 171

Explain two differences between wood chips and coal as an energy resource (2)

Answer 171

coal: carbon dioxide emitted AND wood: carbon neutral or less carbon dioxide emitted;
coal: more energy dense (than wood);
coal: releases sulfur dioxide or NOx / leads to acid rain AND wood: does not;

Question 172

Describe how the student can use a quadrat to record the number of different plant species (5)

Answer 172

quadrats:
quadrat of stated dimensions, e.g. 1m2;
quadrat placed at, regular intervals / stated intervals;
sample all (three) transects;

counting:
count the number of species (in the quadrat);
description of how to deal with plants partially in an quadrat;

recording:
record number in a table;

repeating:
repeat same investigation;
repeating on different days;

Question 173

State the name of the equipment used by the student (1)

Answer 173

pooter;

Question 174

The student wants to compare the number of different types of insect on the leaves of plants at the beginning and end of each transect. Suggest how the student can ensure that the comparison is fair (2)

Answer 174

same plant species / same type of plant;
same number of leaves;
same size of leaves;
same time of day;
same person;
same plant height;
examine each leaf for same period of time;
count / identify, the number of types of insect;

Question 175

Explain why plants are called producers (2)

Answer 175

photosynthesis;
chlorophyll absorbs light energy;
reactants: carbon dioxide and water;
products: glucose and oxygen;
light energy to chemical energy;

Question 176

Explain the flow of energy through this food web (3)

Answer 176

energy transfers when organisms eaten / stated example of feeding from food web e.g. plant eaten by rabbit;
lost as heat;
idea of only 10% of energy passed between levels / 90% is lost;

lost through:
respiration;
digestion;
(excreted) waste (products); movement;
death / decomposition;
maintaining body temperature / thermoregulation;
feeding / consumers do not consume the whole organism;
reproduction;

Question 177

Explain how seed banks and zoos can help to maintain biodiversity (6)

Answer 177

(both) prevents extinction / protects endangered species;
seeds / animals can be reintroduced into wild;

seed banks:
maintains genetic record / source of genes;
development of new plants, e.g. drought-resistant wheat;
development of medicines;

zoos:
allows (captive) breeding;
reduces impact of, predation / hunting / poaching;
prevents inbreeding / international cooperation;
education / awareness;

Question 178

Explain what may happen to the haddock population if the mesh size of the gill net is not
regulated (3)

Answer 178

population likely to decline / overfishing;
small mesh size catches young fish;
not able to breed;

Question 179

State three strategies, other than regulating mesh size, that can be used to control fishing in Denmark (3)

Answer 179

area or total size of net;
quotas;
closed seasons;
protected areas;
licenses;
international economic exclusion zone (EEZ);
size of boats / number of boats / CCTV on boats / patrols / monitoring / tracking of boats / number of fishing days;

Question 180

Some fish are processed into fish meal. Fish meal has a high protein content. It is used to feed animals on farms to help them grow
quickly. Give two reasons why some people think this is not a sustainable activity (2)

Answer 180

overfishing / will run out of fish / population of fish decreases;
many species are caught that are not eaten / a lot of bycatch;
lead to overproduction of farm animals;
removing many species of fish impacts food chains;

Question 181

Describe the benefits and limitations of fish farms (4)

Answer 181

benefits:
increased food supply;
less work / less use of energy (than going to sea);
safer (than going to sea);
no bycatch;
preserves wild stocks;
allows harvesting all years / no seasons;
not weather-dependent;

limitations:
pollution from, organic matter / fish meal / oil / pesticides / waste / antibiotics;
spreads disease;
risk of escape;
impact on food chain;

Question 182

Suggest reasons why Laos has a rapidly increasing population (3)

Answer 182

Laos is an LEDC;
economic growth (of country or for people);
lack of, contraception / family planning resources;
improved or good healthcare;
improved or good, access to safe drinking water / sanitation;
improved or good, infrastructure / access to electricity;
migration (into Laos) / immigration;
job opportunities;
pronatalist policies / policies to encourage large families / no antinatalist policies / financial incentives to have children

Question 183

Suggest the environmental advantages of using hydroelectric power rather than coal to generate electricity (3)

Answer 183

does not produce, carbon dioxide / greenhouse gases;
does not contribute to global warming / (enhanced) greenhouse effect / climate change;
does not produce sulfur dioxide / oxides of nitrogen;
does not contribute to acid rain / smog;
renewable resource;
less visual pollution (due to less mining);
idea of sustainability / reserves of coal left (for future generations)

Question 184

Suggest economic benefits of dams for local people (3)

Answer 184

increase the supply of electricity;
employment;
tourism opportunities;
improved infrastructure;
reduced flooding (so less damage to farms / crops / homes);
stated economic benefit to farmers e.g. silting so no need to buy fertilisers / idea of improved or high crop yield (due to better irrigation);

Question 185

Suggest three reasons why many people were affected when the dam burst (3)

Answer 185

people live / densely populated, near dam;
large area flooded / large volume of water;
no early warning / no disaster plan;
dam was poorly constructed;
bridges / roads / power supply / infrastructure, destroyed;
homes destroyed / people left homeless;
people could not evacuate / happened at night / people were asleep / no evacuation plan;
no medical help / aid could not reach area / no rescue teams;

Question 186

Suggest reasons why the number of deaths caused by this disaster increased in the long term (4)

Answer 186

lack of adequate shelter / exposure;
poor sanitation / lack of clean water;
spread of (water related) diseases / named disease; e.g. cholera, typhoid
lack of access to, medicines / medical facilities / hospitals / medical treatment;
loss of crops or food or farmland / starvation / famine / land underwater so cannot crops cannot be planted;
loss of jobs / loss of income / no money to pay for flood recovery

Question 187

State four factors that affect the cost of extraction of minerals (4)

Answer 187

idea of difficult to extract due to geology: e.g. depth or hardness of surrounding rock / overburden / terrain;
accessibility (to site) e.g. lots of rivers to cross
legislation / taxes / licences / permits;
availability of workers / idea of hourly rate paid to workers;
type of extraction or mine or mining / whether it is surface or subsurface
use of machinery;
waste disposal;
quality of rock / grade of rock / how much of the rock contains the mineral / amount of mineral present in the rock / ore contains unwanted material or toxic material

Question 188

Describe the process of restoring an open-pit surface mine to a forest after mineral extraction has finished (4)

Answer 188

idea of filling pit using, mining waste / overburden / rocks;
cover with (top)soil;
improve soil / add organic matter / add manure or fertiliser;
bioremediation / cleaning of polluted soil;
plant, grass / vegetation / trees / seeds;
irrigate or water vegetation;

Question 189

Suggest reasons why the annual fish consumption per person varies in different countries (3)

Answer 189

availability of, fish / other food sources / land-based protein;
high cost / tax on fish / ora other food;
cultural reasons / traditions / fashion / trends;
idea of ease of storage e.g. availability of refrigeration;
idea of fish is not safe to eat / polluted waters;

Question 190

The African catfish is not normally found in the wild in Laos. Suggest the limitations of using the African catfish for fish farming in Laos (4)

Answer 190

may not tolerate or be adapted to local conditions / local conditions not suitable;
large or heavy so difficult to handle / need large space;
may require, a lot of food / specialist food / lack of usual diet;
low reproductive success / difficult to breed;
risk of disease (from or to other species);
compete with wild population / disrupt food web / have no natural predators / become invasive (if they escape);
cost of, importing / transport;

Question 191

Explain why fish farming is more sustainable than catching wild fish (2)

Answer 191

catching wild fish less sustainable as can lead to:
overfishing / stock depletion / (wild) fish population increases;
reduction in breeding;

fish farming more sustainable as:
higher-yielding / can harvest all year round;
less bycatch / reduces risk of catching juveniles

Question 192

Describe one way the fish farmer can select a representative sample of local people to answer the questionnaire (2)

Answer 192

use a, systematic / random, sampling method;
method described:
random: number generator / names in hat
systematic: every nth person;

Question 193

Explain why the fish farmer decides not to change the species of fish being farmed (3)

Answer 193

only half the people eat / fish demand for fish is, low or equal;
demand for fish is not increasing / people do not eat more fish (in 5 years);
most people won’t, try new species / change ways;
farmer would lose income / not many people would buy (new) fish;

Question 194

State three abiotic factors that affect the growth of farmed fish (3)

Answer 194

temperature;
water;
oxygen (level);
salinity;
light (intensity);
pH (water);

Question 195

Explain why the farming of plant-eating fish is more energy efficient than the farming of insect-eating fish (2)

Answer 195

plant-eating fish: at lower trophic level / eat producers / are primary consumers;
energy is lost / 90% energy lost / 10% energy transferred, between trophic levels
energy lost as heat / movement / respiration other named process;

Question 196

State the name of the strategy used to reduce soil erosion which is shown in the photograph (1)

Answer 196

terracing;

Question 197

State four strategies that can be used to reduce soil erosion (4)

Answer 197

terracing;
maintaining vegetation cover / planting vegetation;
adding, organic matter / manure;
mixed cropping / intercropping / crop rotation;
wind breaks;
contour ploughing;
improved irrigation or named example e.g. trickle drip;
bunds;
reduction in grazing;

Question 198

State how the activities shown in the photograph affect surface run-off and evaporation (2)

Answer 198

surface run-off:
reduced or slowed AND due to reduced gradient / less slope;

evaporation:
increased AND due to, large surface area / open to the sun;

Question 199

State the names of processes A and B (2)

Answer 199

A transpiration;
B precipitation;

Question 200

Suggest three ways the student can confirm the results of the investigation (3)

Answer 200

repeat same experiment;
greater number of trees / more than 5 trees;
different tree species;
different, soils / locations;
continue over longer time period / carry on over more years;

Question 201

Explain how afforestation helps with the management of atmospheric pollution (5)

Answer 201

increasing number of trees;
trees photosynthesise;
reduces concentration of (atmospheric) CO2 / trees capture carbon
more trees reduces impact of (enhanced) greenhouse effect / global warming;
trees act as carbon sink or store;
trees trap particulate matter;

Question 202

Suggest three reasons why people migrate to The Bahamas (3)

Answer 202

conflict / refugees;
economic;
employment;
family;
favourable climate;
health care / hospitals;
education / schools

Question 203

State two sources of fresh water that can be used in The Bahamas (2)

Answer 203

aquifers;
reservoirs;
lakes;
rain water (harvesting);
desalination (plants);

Question 204

Describe the benefits and limitations of using water barges to meet the demand for fresh water (4)

Answer 204

benefits:
simple technology;
easy (to transport);
water can be pre-treated;

limitations:
weather dependent;
risk of contamination;
uses (fossil) fuels / energy required for transport;
transport is slow;
limited number of barges / idea of disrupted supply of barge out of service;

Question 205

Explain why the energy in the body of the flamingo is dependent on chlorophyll (4)

Answer 205

(chlorophyll) in, producer / phytoplankton;
needed for photosynthesis;
uses carbon dioxide and water;
uses (Sun) light (energy);
to produce, glucose / sugar / (store) chemical energy;
energy moves (along food chain);

Question 206

In the 1950s, scientists studied a population of Caribbean flamingos on Inagua Island. The scientists found that the population was decreasing and in 1956 only 100 flamingos
lived on Inagua Island. Suggest strategies to protect the Caribbean flamingos on Inagua Island (4)

Answer 206

preserve habitat;

introduce:
national parks;
captive breeding / zoos ;
wildlife, wardens / guides;
laws to give them protected status;

control:
disturbance by people / limit numbers of tourists;
predators e.g. vultures;
shrimp fishing;
hunting / fines for illegal poaching;

Question 207

Describe a method for estimating the population of Caribbean flamingos on Inagua Island (5)

Answer 207

described method of dividing island or lake;
random / systematic sampling or method described;
count the number of flamingos;
at a set time or date;
record results, in a table / using a tally system;
idea of scaling up to whole area;
repeat and average;

Question 208

Suggest how air temperature can affect the salinity of the lake (2)

Answer 208

the higher the temperature, the greater the evaporation of water;
(as water evaporates) the salinity or concentration increases;

Question 209

Suggest reasons why the person thinks that oil processing should be encouraged in The Bahamas (3)

Answer 209

jobs;
personal economic reason;
national economic reason e.g. increase GDP;
can be export;
creates infrastructure;
processed product in more demand;

Question 210

Describe the formation of oil (3)

Answer 210

millions of years ago;
(remains of small) animals / plants / organisms AND deposited on sea floor;
covered with, sand / mud / sediment (to form rock);
heat AND pressure (converted to crude oil);

Question 211

Explain how oil is used to generate electricity (3)

Answer 211

(oil) combusted / burnt;
heat is used, to boil water / produces steam;
steam, turns / drives / moves / runs, a turbine;
turbine, turns / drives / moves / runs, a generator;

Question 212

Identify two possible causes of marine oil pollution in The Bahamas (2)

Answer 212

pipelines;
shipping at sea;
cleaning tanks at sea;
oil processing plant;
(offshore) oil extraction / oil rigs;

Question 213

Describe the impact of oil pollution on the coral reefs in The Bahamas (4)

Answer 213

oil covers coral / organisms;
oil is toxic;
oil stops, light from getting to coral / photosynthesis;
oil stops corals from filter feeding;
no food for consumers;
no nursery area for breeding organisms;
disrupts food web / food chains / biodiversity;

Question 214

State three strategies used to minimise the impacts of oil spills (3)

Answer 214

MARPOL;
double hull tankers;
booms;
detergents;
skimmers;
burning;

Question 215

Suggest three ways that the survey can be improved (3)

Answer 215

more questions;
ask open questions;
larger sample size / ask more people / make sample more representative;
ensure participants are residents / make sure tourists are not surveyed;
survey equal numbers of, different age groups / males and females;
repeat on different days;
repeat in different locations;

Question 216

Explain two other strategies the government can use to manage the harvest of spiny lobsters (4)

Answer 216

strategies:
limit size of lobster you can harvest / only catch larger lobsters;
protect female lobsters (with eggs);
quotas;
closed seasons;
protected areas and reserves;
conservation laws, e.g. licences for harvesting;
monitor and enforce;

explanations that fit the strategies:
allows immature lobster to reach breeding age;
females produce massive amounts of eggs / one male can fertilise eggs from many females;
prevents overfishing;
allows lobster to breed;
allows larvae to spread from protected area;
limits the number of, fishermen / fishing days / boats;
ensure people are following the rules;

Question 217

Suggest two reasons why scientists do not expect the lionfish population to increase greatly after 2020 (2)

Answer 217

limited, food supply / spiny lobster;
reached carrying capacity;
disease;
control methods introduced e.g. hunted;

Question 218

Describe the benefits and limitations of this method for controlling the population of lionfish (5)

Answer 218

benefits:
biological control;
sharks prey regularly on lionfish / no further training needed;
only lionfish killed / no bycatch;
job / income, opportunity;

limitations:
requires divers to train sharks;
could be dangerous for the diver;
training sharks is difficult;
expensive;
labour intensive / time-consuming;
population of lionfish is too high / lionfish can reproduce too quickly;
lionfish spread over too large of an area;

Question 219

Explain why the climate of Spain is suitable for growing vegetable (3)

Answer 219

hot / warm / high temperatures (for growth);
high rainfall (for growth);
(conditions suitable for) photosynthesis / stated equation / to produce glucose;
irrigation / water can be stored;

Question 220

State how the concentration of mineral ions can be improved in soils (1)

Answer 220

fertiliser / organic matter / crop rotation / plant legumes;

Question 221

Complete the table to describe the characteristics of sandy soil (3)

Answer 221

ease of cultivation: easy / quickly loses nutrients / low nutrient value;
drainage: quick / fast / good / high / does not hold water;
air content: high / good / holds a lot of air;

Question 222

Suggest reasons why people are not allowed to walk on the sand dunes (2)

Answer 222

trampling / dunes could collapse ;
kills or disturbs, plants / animals;
loss of habitat(s) ;
loss of some species / extinctions;
may drop litter;
introduces invasive species;

Question 223

Suggest how plants are adapted to growing in the sand dunes (1)

Answer 223

salt-tolerant;
drought-tolerant / plants conserve or store water;
wind-resistant;
deep roots / wide roots;
fast growing, plants / roots ;

Question 224

Explain how climate change is a threat to the sand dunes (4)

Answer 224

increase temperatures;
leads to melting of ice caps / increased sea level;
leads to flooding / sea covers sand dunes / dunes drown ;
leads to (conditions that favour) invasive species
extreme weather;
leads to stronger winds / storms;
leads to increased waves;
erosion of sand;
more salt on plants;
greater competition (for resources);
can’t adapt fast enough / conditions are too extreme;

Question 225

In the past, sand was removed from the sand dunes to be used in many different
industries. State why this was not a sustainable practice (1)

Answer 225

compromised the ability of future generations to meet their own needs / didn’t leave sand for future (generations) ;

Question 226

The company sends the questionnaire to every woman within 100km of the planned
factory location. Describe the limitations of this method (2)

Answer 226

only women questioned / not a representative sample ;
leads to biased results;
too much data;
will be expensive to conduct / analyse;

Question 227

Explain why yes or no answers are used on questionnaires (1)

Answer 227

easier / quicker, to collect or analyse or process answers;
consistency of answer;
limits possible answers;

Question 228

Suggest why most local people want the factory to be built even though it may damage the ecosystem of the sand dunes (2)

Answer 228

employment;
improvement in local or national economy;
improvement in facilities / infrastructure;

Question 229

Describe a method the scientist can use to determine the number of plant species along the 10-metre transect line in the sand dune reserve (4)

Answer 229

use of transect and quadrat:
divide the transect, systematically / in equal distances / stated distances;
defined size of quadrat, e.g. 25 cm x 25 cm, 50 cm x 50 cm, 1 m x 1 m;
count the number of plant species, every stated distance / in quadrat;

recording and processing data:
record the results, in a table / using a tally;
use a book to identify species;
repeat and take a mean;

Question 230

Suggest reasons why using the data in the table is likely to give an underestimate of the total number of species in the 10km2 sand dune reserve (3)

Answer 230

the method only covers five (small) areas;
five transects are not representative;
lot of sand dune not sampled;
plants not evenly distributed;
longer transect needed (across whole area);

Question 231

Suggest reasons why countries import electricity (2)

Answer 231

cannot meet demand
due to increased population;
cost / shortage, of fossil fuels;
lack, of renewables;
cheaper to import than to generate;

Question 232

Suggest one disadvantage of importing electricity (1)

Answer 232

economic impact / cost;
lack of energy security or described;

Question 233

Describe advantages and disadvantages of using wind turbines to generate electricity compared with using fossil fuels (4)

Answer 233

advantages:
renewable;
does not emit CO2 (at point of use);
so does not contribute to climate change;
does not emit SO2 / NOx;
so does not contribute to acid rain;
land around wind turbines can still be used;

disadvantages:
not suitable if no wind or not strong / powerful enough;
wind needs back up generation;
turbines in area of natural beauty / visual / noise pollution;

Question 234

Suggest the problems with disposing of waste oil (4)

Answer 234

buried in landfill takes up takes space;
oil, leakage / spillage;
toxic (to humans/animals);
named toxin: benzene / lead / chromium / arsenic / dioxins / heavy metals;
burning produces atmospheric pollution;
named pollutant CO2 / NOx / VOCs, / SO2 /  hydrocarbons / CO / smoke / particulates;
named effect on human health, e.g. cancer risk / damage liver / respiratory problems / skin irritation ;
(oil) contaminates / pollutes, land / soil / water
animals, suffocate / covered in oil or reduces development of animals;
disrupts, food supply / food chain / ecosystems;

Question 235

Describe strategies for the efficient management of existing energy resources (4)

Answer 235

reduce consumption;
by turning off electrical devices;
insulation of homes / name example;
use energy efficient devices / vehicles;
educate people on energy consumption;
invest in / use more, renewables;
increase taxes on fossil fuels;
recycle to reduce energy use / stated example;
generating electricity from waste products;

Question 236

Describe a selective breeding method to increase the mass of sheep (4)

Answer 236

select (two) sheep with the greatest mass;
breed the sheep;
choose offspring with the greatest mass;
repeat / breed these offspring;

Question 237

State three causes of deforestation (3)

Answer 237

pastoral farming;
timber extraction / logging;
roads;
urbanisation / homes / industry;
rock / mineral extraction;
fuel;

Question 238

Explain the impacts of deforestation on the carbon cycle (4)

Answer 238

reduction in photosynthesis;
(trees act as) carbon sink or store;
fewer young or growing trees to remove / fewer mature trees store so more CO2 or carbon ;
change in decomposition (of leaves);
change in carbon added to the ground;
(deforestation leads to) increased carbon dioxide in atmosphere ;
imbalance between respiration and photosynthesis;

Question 239

Describe how captive breeding programmes can increase the number of European brown bears (2)

Answer 239

young less likely to die from disease / access to vaccination;
other stated medical support;
breeding support / increased gene pool;
no threat from predators / hunting / poaching ;
not released into the wild until mature / strong;
no lack food / good food supply;

Question 240

Describe what causes a volcano to erupt (3)

Answer 240

(tectonic) plates move / at plate boundaries;
pressure of magma;
Earth’s crust is thin;
magma rises ;
comes out / breaks through the, crust / cracks / vents;
(as) molten lava / ash ;

Question 241

Suggest reasons why each island in the Canary Islands is smaller than when it first formed millions of years ago (2)

Answer 241

erosion;
erosion by (sea) water / wind;
sea level rise;

Question 242

State the meaning of tsunami (1)

Answer 242

a large wave ;

Question 243

State the name of the scale used to record the magnitude of an earthquake (1)

Answer 243

Richter / Moment Magnitude (scale);

Question 244

Some scientists think there is only a low risk of a large-scale landslide at La Palma. Suggest reasons why (2)

Answer 244

earthquakes are only low on the scale / between 1.5–2.7;
valid comment about magnitude needed to increase the risk / eq;
e.g. terraces reduce risk of landslide

Question 245

Describe the possible impacts of a landslide and tsunami on the island of La Palma (3)

Answer 245

flooding;
death / injury;
from drowning / rocks falling;
evacuation;
damage to buildings;
damage to agriculture, e.g. crops, farmland, livestock;
damage to infrastructure, e.g. communications, transport networks;
loss of jobs / damage to the economy ;
e.g. cholera / typhoid / water borne disease OR loss of biodiversity;

Question 246

State three strategies for managing the impacts of a tsunami (3)

Answer 246

monitoring stations;
warning systems;
evacuation (plan);
(evacuation) drills;
(emergency) rescue teams;
(emergency) shelters;
stores of food and water;
medical aid ;
build seawalls / only build on high ground;

Question 247

Suggest why this farming of cochineal beetles is an example of sustainable farming (2)

Answer 247

it can continue for a long time / multi-generational / beetles can reproduce;
no degrading of soil / eq;
no use of, fertilisers / pesticides;

Question 248

Use the photograph to explain why this is an example of good agricultural practice (3)

Answer 248

terraced fields;
trees / vegetation hold soil / prevent erosion;
prevent soil erosion;
maintain fertility;
irrigation used;
by gravity / without need for pumps / using bunds / walls;
bunds / walls used;
prevent (wind) erosion / help, shelter trees / vegetation;

Question 249

Explain the impact of waterlogged soil on crop production (3)

Answer 249

reduces (oxygen concentration in) air spaces;
roots cannot respire;
kills (roots of) crops / drowns crops;
causes plants to become shallow-rooted;
causing salinization;
and compacts soil;
reduces crop yields;
soil is washed away;
minerals are lost from the soil;
decreases fertility;
kills worms and other organisms in soil;

Question 250

State three uses of the land shown in the photograph (3)

Answer 250

housing / businesses / shops / named example;
recreational;
roads;
small fields / agricultural;
forest / wild / conservation areas;

Question 251

Suggest why food production cannot be increased at the location shown in the photograph (2)

Answer 251

many steep slopes / mountainous;
without soil / infertile;
machinery cannot be used;
infertile soil / no soil to anchor roots;
most suitable land already used / named example of use;

Question 252

Up to 90% of the food needed in the Canary Islands is imported. Suggest one other item that needs to be imported (1)

Answer 252

(fossil) fuel;
building materials;
manufactured goods, e.g. cars;
medical supplies;

Question 253

An environmental impact assessment is needed at each possible wind turbine location
before building can begin. Explain why an environmental impact assessment is needed (2)

Answer 253

to find out people’s views on building;
to survey the wildlife;
will lose habitat;
check no endangered species
to protect local activities such as farming;

Question 254

Describe other benefits of using wind power to generate electricity (2)

Answer 254

no carbon emissions / GHG’s / does not contribute to global warming;
no acid rain gases;
reduces need to import, fossil fuels / oil;
readily available / lots of wind on islands;

Question 255

Describe a suitable method for selecting tourists to answer the questionnaire (2)

Answer 255

random or systematic specified;
correct description matching method specified, e.g. use a random number generator, ask every fifth tourist;

Question 256

Describe one benefit of using the questionnaire when tourists arrive and when tourists leave the island (2)

Answer 256

to see if their opinions have changed;
to decide when to charge the tourist tax;
to check if the findings are similar to the sample of people arriving at the airport;

Question 257

Explain ways tourism can be made a sustainable activity (4)

Answer 257

developing sewage treatment;
offsetting carbon emissions;
encouraging ecotourism;
using renewable energy resources;
recycling waste caused by tourism, e.g. plastic bottles / litter collection;
educating, local people / tourists;
employing environmental guides / wardens;
funding to maintain natural beauty areas, e.g. forest, beaches;
(create a) national park / nature reserve / eq;
e.g. bikes / electric cars / laws against littering / prevent hunting;

Question 258

Discuss whether tourism contributes to climate change (5)

Answer 258

Yes
transport, e.g. planes and cars;
(combustion of fossil fuel) produces CO2 / GHG’s;
construction of materials for hotels, e.g. cement;
more energy / electricity (used on luxury items, e.g. swimming pools, saunas);
land is cleared for buildings;
fewer, trees / plants;
so less photosynthesis / eq; e.g. less carbon dioxide absorbed
destruction of carbon stores / sinks;
(intensive) farming practices to supply food for tourists;
increased methane from cattle;
e.g. burning more fossil fuels

No
tourists would release similar amounts of C in their own country;
if they have enough money they will consume goods that may have contributed to climate change in their manufacture
anyway;

Question 259

Suggest why people living on small islands are very worried about climate change (2)

Answer 259

(small) sea-level rise / extreme weather / hurricanes
limited land available so effects of climate change more pronounced;
causing flooding (of coastal plains);
loss of homes;
forced migration;
loss of farmland;
contamination of fresh water sources;
must move inland (near volcanoes);

Question 260

Suggest reasons why 60% of the population in Guinea is under the age of 25 (2)

Answer 260

high population growth rate;
high birth rate;
low life expectancy;

Question 261

Suggest two impacts of a youthful age structure on a less economically developed country (LEDC) (2)

Answer 261

expensive healthcare needed, e.g. immunisations;
lack of hospitals;
puts pressure on education system / large class sizes / more teachers needed;
lack of jobs;
overcrowding;

Question 262

Describe three pieces of evidence in the photograph that suggest Guinea is a less
economically developed country (LEDC) (3)

Answer 262

road made of dirt / not tarmac;
no motor transport / only animal transport;
(cart/one person) can only carry a small load;
no, lighting / drainage;
rubbish by road;
simple buildings / buildings close together / homes built of poor materials

Question 263

Describe the process of photosynthesis (4)

Answer 263

inputs:
carbon dioxide (from air through leaves);
water (from soil through roots);
chlorophyll / chloroplasts;
(chlorophyll / chloroplasts) trap energy from the Sun / light energy / light energy converted to chemical energy;

outputs:
glucose;
oxygen;

Question 264

Describe the process of pollination in peanut flowers (3)

Answer 264

pollen / male sex cells;
moves from anther;
to stigma;
in same flower / from flowers on same plant;

Question 265

Suggest one benefit of exporting peanut oil instead of peanuts (1)

Answer 265

higher value / lower transport cost / easier to transport a liquid / more demand / longer shelf life;

Question 266

Suggest two possible uses for the peanut waste after the peanut oil has been extracted (2)

Answer 266

biomass fuel;
feed for animals;
fertiliser;
mulch;

Question 267

Suggest reasons why the government of Guinea encourages farmers to grow peanuts (2)

Answer 267

keeps people employed;
country / government earns, money / taxes / increase GDP / foreign exchange;
so more to spend on infrastructure / named example

Question 268

Suggest why the farmers expect the yield of peanuts to go down after several years (2)

Answer 268

no crop rotation;
(same) minerals removed each year;
drop in fertility / nutrient deficiency;
other reference to damaged soil, e.g., compaction / soil erosion;
increased pest / disease;

Question 269

The stems and leaves of the peanut plants can be used to feed livestock. Suggest how this helps make peanut farming a sustainable activity (2)

Answer 269

no waste;
don’t need (to buy) as much food for animals;
animals produce meat / milk;
manure goes back onto land as a fertiliser;
not relying on one form of income;
ref. to food security;

Question 270

Some peanut farmers are not able to keep livestock. Suggest other ways these farmers can make their farming sustainable (2)

Answer 270

mixed / intercropping;
crop rotation / leave fallow;
improved irrigation / named improved irrigation technique, e.g. trickle drip;
grow pest resistant varieties;
green manure / legumes;
peanut waste as, fertiliser/compost / add an organic fertiliser;
grow other crops;
agroforestry;

Question 271

Describe how the pooter shown in the diagram is used to collect insects (3)

Answer 271

suck tube on left / suck air through pooter;
insect gets sucked in other tube;
gauze prevents insect entering mouth;
insect falls / trapped, in pot;

Question 272

Describe a method the student can use to select the peanut plants at random from each field (2)

Answer 272

divide the field into areas / grid squares;
use random number generator / dice to select grid squares to be sampled;

Question 273

State one strategy for reducing soil erosion (1)

Answer 273

bunds;
terracing;
contour ploughing;
wind breaks;
maintaining vegetation cover;
add organic matter / mulching;
planting trees;
mixed cropping / intercropping / crop rotation;

Question 274

Suggest two benefits of making the building blocks hollow (2)

Answer 274

can make more blocks / less material needed;
air in holes reduces conduction / blocks provide more insulation;
lighter / less dense;
less drying time / quicker / easier (to dry);

Question 275

Suggest two advantages of making the building blocks by machine (2)

Answer 275

quicker / more blocks can be made;
blocks have uniform shape;
machines can compress more tightly;
lower labour cost;

Question 276

Explain how releasing carbon dioxide into the atmosphere contributes to the enhanced greenhouse effect (3)

Answer 276

carbon dioxide is a greenhouse gas;
absorbs / traps, (long-wave) radiation;
(more) heat is retained within the atmosphere / less heat is released;
increases global temperature;

Question 277

An advantage of using wood for building is that it limits the use of cement. Suggest two other ways the government of Guinea can limit the use of cement (2)

Answer 277

limit who can make or sell it / licences;
nationalise;
increase prices;
taxation;
use of a named alternative e.g. stone, mud, clay, animal waste

Question 278

Suggest two disadvantages of using wood for building (2)

Answer 278

encourages, deforestation / illegal logging / habitat destruction / loss of biodiversity / soil erosion;
contributes to greenhouse effect;
wood should only be available from sustainable sources;
host to termites or other pests;

Question 279

Suggest reasons why there is less risk of injury and death working in an open-pit mine compared with working in a shaft mine (2)

Answer 279

in open-pit less risk of:
collapse;
suffocation / build-up of dangerous gases;
explosions;
flooding;

Question 280

Suggest reasons why local people want diamond mining to continue in the area (2)

Answer 280

for jobs / employment / job security;
to improve infrastructure of area;
bring money to the area / increase standard of living of local people / income;

Question 281

Explain why an environmental impact assessment must be completed before a mining licence can be issued (3)

Answer 281

to make sure, damage to environment is limited/eq;
is temporary / ref. to restoration;
not a cause of serious pollution / to reduce or control pollution;
does not destroy habitat;
ensure no endangered species / does not endanger species;
to ensure safety standards;
to know how waste will be dealt with;
to listen to local people’s views;

Question 282

Describe ways the landscape shown in the photograph can be restored after all the mining is finished (4)

Answer 282

landscape to make shape more natural;
use as a lake for, fish / water supply / recreation;
fill hole with, overburden / waste rock / land fill site;
cover with topsoil;
use fertilisers;
plant seeds / grasses / plants;
then shrubs and trees;
soil improvement;
bioremediation;

Question 283

Describe strategies for the sustainable use of rocks and minerals (4)

Answer 283

recycling / reuse;
improved efficiency of extraction / secondary extraction;
improved efficiency of use;
using alternatives;
legislation;
do not exhaust a supply / save some for future generations;
quotas on extraction;