Environmental Systems and Societies

Dulwich College Shanghai
SCIENCE DEPARTMENT

Environmental Systems and Societies

Standard Level

Paper 1

Mock Examination

1 hour

Instructions to Candidates:

· Do not open this examination paper until instructed to do so.

· Answer all of the questions in the spaces provided. You may continue your answers on lined paper. Write your name on each sheet of lined paper, and attach them to this examination paper.

1. Figure 1(a) shows a farming system and Figure 1(b) outlines the activities for the farm in

areas A, B and C over a year.

Figure 1(a)

Figure 1(b)

(a) State, giving two reasons, whether this system is more typical of farming in a more

economically developed country (MEDC) or a less economically developed country (LEDC).

[2]

LEDC

basic/lack of technology generally;

rice farming is typical of LEDCs / where rice is often the staple crop;

cash crops for export such as sugar cane, tobacco;

houses look fairly simple and made from local / cheap materials / thatched roofs;

dependence on working animals;

labour intensive (family labour);

mixed cropping on small scale;

Award [0] for only stating LEDC.

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(b) Complete the systems diagram below to show three inputs, processes and outputs for the

farming system shown in Figure 1(a) and Figure 1(b). [3]

inputs: [1 max]

water / technology / cattle (livestock) / sunlight / rain / manure / seed / labour / soil;

Award [1] for any three of the above.

processes: [1 max]

planting / ploughing / harvesting / irrigating / repair / respiration / run-off / labour;

Award [1] for any three of the above.

outputs: [1 max]

jute / vegetables / mangoes / Jack fruit / Palm / coconut / sugar cane / spices / crops /

waste / income / energy / rice / food / Betel nuts / tobacco / cattle (livestock) / heat /

oxygen / carbon dioxide / wheat / mustard;

Award [1] for any three of the above.

system has been developed in response to variations in the local environment. [2]

different crops planted at different levels;

rotation of crops to match seasonal rainfall patterns;

monsoonal climate so main crop is rice;

irrigation technology used in dry season;

livestock fed differently at different times of year;

different jobs done at different times of year; [2 max]

Accept other reasonable answers.

Answers must be linked to variations in environment.

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Figure 1(c) below shows nutrient cycling in a terraced paddy.

(d) With reference to Figure 1 (c), define

(i) leaching. [1]

when nutrients, dissolved in water, wash down through the soil/paddy and are lost;

(ii) nitrogen fixation. [1]

process by which nitrogen in atmosphere is fixed to form nitrate by

blue-green algae (and converted into a useable form for plants);

(e) With reference to Figure 3 explain the following.

(i) There is very little soil erosion in this farming system. [1]

because the terraces are level there is little run-off by water so soil is not

washed away / terraces prevent soil erosion / soil collects in paddies;

(ii) The dead organic material breaks down more rapidly in the oxidized zone. [1]

oxygen is required by decomposers to break down organic matter (the

oxidized zone is closer to the surface and richer in oxygen) / higher BOD in

oxidized zone as more decomposers, thus more decomposition;

2. Owls are predators that hunt mainly at night. They feed on small mammals such as mice, voles

and shrews. The owls vomit up pellets which contain the parts of the prey that they cannot

digest, such as jaw bones. These jaw bones can be used to identify prey species.

Figure 2(a) below shows how an owl produces a pellet and Figure 2 b) shows the features of

the mammal jaw bones used to identify the owl’s prey.

Figure 2(a) Figure 2(b)

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(a) Using the key, identify the prey species A to F from the lower jaw bones found in owl pellets,

from an open European woodland. [3]

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(b) To estimate the populations of small mammals in a woodland, ecologists set traps in the area

before sunset and the following morning marked all the captured animals before releasing them again.

(i) State what information the ecologists must record before releasing the animals. [1]

number of animals of each species captured;

Must include both number of animals and indication that more than one

species is likely to be captured for [1].

(ii) A week later the traps are set again as before. State what data must be recorded when the

traps are opened and explain how these data may be used to estimate the small mammal

populations in the area. [2]

number of animals of each species captured and number marked from each species;

(iii) A student suggests that the relative abundance of jaw bones from different prey species

found in owl pellets might be proportional to the relative sizes of the populations of those species.

Suggest two reasons why data from owl pellets may not reflect the relative sizes of the small mammal populations in an area. [2]

some small mammals species may be caught/eaten more often than others

by owls because they;

move more slowly;

are easier to see than other species;

forage for food/are active at night;

forage in open areas with little cover;

are bigger/more nutritious (so preferred by owls);

range of owl foraging may be very wide / area of foraging;

sample of pellets may be too small to see full range of species;

relative sizes of prey populations may vary through the year;

3. (a) Distinguish between the terms ecological footprint and carrying capacity of a human

population. [2]

carrying capacity is the maximum population/number of humans/“load” that can be sustainably supported by a given environment/area;

ecological footprint is the area (of land and water) required to support a (defined) human population (at a given standard of living);

carrying capacity and ecological footprint are the inverse of each other /

(b) For the resources listed below, identify whether each is considered to be renewable, non-

renewable or replenishable. Groundwater is shown as an example. [2]

Groundwater: .....……… Replenishable ……………..

Rice crop from a paddy field: renewable;

Copper minerals in rocks: non-renewable;

Animal wool: renewable;

Ozone layer: replenishable;

Award [1] for each two correct identifications.

transfer processes: (flow through a system) move materials/energy from one place to another/involve a change in location;

transformation processes: lead to (an interaction within a system in) the formation of a new end product/involve a change of state;

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Figure 3 below shows a freshwater lake in a temperate forest biome, close to an ocean.

(ii) Annotate the diagram below to show the natural transfer and transformation processes

which move water from the ocean to the lake. [2]

Award [1] for each two correct processes.

(iii) The land around the lake is used for livestock farming. State and explain one impact this

may have on the lake ecosystem. [2]

impact:

increased turbidity/biochemical oxygen demand (BOD);

explanation:

caused by animals entering lake/addition of organic matter from feces/field run-off;

impact:

increased levels of inorganic nutrients/phosphates/nitrates/eutrophication /

changes due to eutrophication;

explanation:

caused by animal urine/feces/soil entering lake; [2 max]

Accept any other reasonable suggestion or good example.

(iv) Suggest two reasons why fresh water supplies may be insufficient to meet the demands

of human societies in the future. [2]

population growth outstripping rate of replenishment;

currently developing countries will need more water as they become more developed;

improved standards of hygiene/health require more water;

some freshwater resources/aquifers becoming contaminated by pollution/ saltwater incursion;

climate change leading to extensive drought/monsoon failure;

Accept any other reasonable suggestion or good example.

4. Figure 4 below shows the estimated size of some global energy flows for one year.

(a) State two processes that reduce the amount of sunlight reaching the Earth’s surface, as the

light travels through the atmosphere. [1]

reflection / scattering / absorption / (dust from) volcanic eruptions / global dimming;

Award [1] for any two processes.

(b) Using the data in Figure 6, calculate, as a percentage range, the proportion of global NPP

used for human food consumption in one year. [2]

conflict/war/civil war/minefields destroys agricultural infrastructure;

differences in climate/soil/water availability for irrigation;

lack of facilities for food preservation/storage in LEDCs;

lack of infrastructure to distribute food in some countries;

political systems that reduce incentives to increase food production;

problems caused by natural hazards e.g. tsunamis / volcanic eruptions / hurricanes /droughts;

problems caused by human impact e.g. increased desertification due to climate change/overgrazing;

sudden availability of food aid may reduce the price of locally produced food to a point where it is uneconomic to produce;

Accept any other reasonable suggestion.

Award [2 max] for responses that use examples to explain above concepts.

5. (a) Define the term environmental impact assessment. [2]

a (detailed) study/investigation/survey required before major development,

to examine environmental impact;

and suggest appropriate monitoring;

should include a baseline survey/study;

Do not accept reference to a document without reference to a survey or study.

(b) Figure 7 below shows three alternative locations for a landfill site (A, B and C).

Choose one landfill site and state two advantages and two disadvantages of your choice. [2]

landfill site A advantages:

close to road/rail;

furthest away from city;

low lying/flat land easier to manage/less visually obtrusive;

landfill site A disadvantages:

scenic coastal location could be spoilt;

prevailing winds could carry smell to city;

at risk from coastal flooding;

could cause coastal pollution;

landfill site B advantages:

close to road/rail;

close to city so short transport time;

low lying/flat land so landfill easier to manage/less visually obtrusive;

wind carries smell away from city;

landfill site B disadvantages:

on flood plain so could be at risk of flooding;

leaching pollutants could contaminate nearby river;

close to city so land may be expensive to buy/needed for expansion;

land likely to be good agricultural land for food production;

landfill site C advantages:

far away from city so fewer people affected by development;

higher land so no risk from flooding;

smell unlikely to carry to city;

landfill site C disadvantages:

near wildlife reserve;

not near road/rail network;

waste must be transported uphill;

site high up so more visually obtrusive;

Award [1] for two correct advantages and [1] for two correct disadvantages.

Do not accept vague responses e.g. pollution without reference to specifics.

Accept any other reasonable suggestion.

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paper/packaging/cardboard;

glass;

metal;

plastics;

organic waste/food;

textiles;

nappies/diapers;

electrical appliances e.g. computers/fridges etc. (WEE);

waste wood;

rubble/bricks;

ash;

Award [1] for any three of the above.

Accept any other reasonable suggestions.

(ii) Discuss the advantages and disadvantages of one named management strategy, other than

landfill, for dealing with solid domestic waste. [2]

recycling:

advantage:

less energy used in recycling metal/paper/glass;

reduces amount of resources used;

maintains stocks of non-renewable/replenishable resources;

disadvantage:

uses energy;

causes pollution;

affected by economic demand and supply factors (and so sometimes

uneconomic);

re-use:

advantage:

little energy used;

provides cheap resources for people of limited means;

disadvantage:

may use some energy to clean;

may be heavy to transport e.g. reusable milk bottles;

eventually wear out/must be disposed of;

composting:

advantage:

produces fertilizer;

reduces volume of waste;

reduces use of chemical fertilizers;

disadvantage:

unpleasant smells / can attract vermin if not done properly;

requires effort/space;

takes time;

Incineration – takes up less space, heat energy generated can be used to produce electricity/energy

Disadvantage: toxic/harmful gases may be released; CO2 emissions contribute to global warming.