Environmental Systems and

Societies

IB1 Exam

Please read this page, but do not open your booklet until your teacher tells you to start. Write your

name in the spaces below.

First name______________________________________

Last name______________________________________

Remember

The test is 1 ½ hours long.

There are 3 sections to the exam:-

Section A – Multiple Choice – answer all questions

Section B – Longer questions – answer all questions

Section C – Essay style question – choose only one question from this

section

Answer all questions on the writing paper provided

Check your work carefully.

Ask your teacher if you are not sure what to do.

There are 11 pages and 1 blank page

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Section A – Multiple Choice

1. Which of the following could be described as an isolated system?

A. The entire universe

B. The planet Earth

C. The biosphere

D. A remote island

2. Which statement describes the result of the first law of thermodynamics?

A. The amount of energy available to do useful work in a system decreases over time.

B. Doing work always creates heat.

C. Total energy input is always equal to total energy output.

D. Energy cannot be recycled.

The diagram below refers to question 3 and question 4. It represents a terrestrial food web

in the deserts of the south-west USA.

3. Which statement is a correct description of the Hognose snake?

A. It is a tertiary consumer only.

B. It is a quaternary consumer only.

C. It is a tertiary and quaternary consumer.

D. It is the top carnivore.

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4. Which of the following organisms named below is part of the trophic level which makes

most efficient use of energy input for that food chain?

A. Garter snake

B. Sparrow

C Rabbit

D. Hognose snake

5. In a European forest, oak tree leaves are eaten by small caterpillars, which are eaten by

small birds (Bluetit), that then are eaten by larger birds (Sparrowhawk).

Which of the following pairs of pyramids are most likely to represent this food chain?

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6. Toxins such as heavy metals are more likely to kill top predators than organisms lower in the

food chain. Which is the best explanation of this effect?

A. Herbivores rapidly excrete heavy metals.

B. Top predators often eat dead animals which may have been poisoned.

C. The digestive system of top predators allows toxins to enter their bloodstream

more readily.

D. Non-biodegradable toxins become more concentrated as they move up the food

chain.

7. Which list shows the major biomes of the world in the correct order of increasing latitude?

A. Hot desert, tropical rainforest, tundra, temperate forest

B. Tropical rainforest, hot desert, temperate forest, tundra

C. Tropical rainforest, temperate forest, hot desert, tundra

D. Tropical rainforest, hot desert, tundra, temperate forest

8. The diagram below represents a balanced model ecosystem.

Which of the following would have to be supplied, from the outside, to enable the aquarium

to act as a model for an ecosystem?

I. Light

II. Carbon dioxide

III. Minerals

IV. Oxygen

A. I only

B. II and IV only

C. I, II and III only

D. I, II, III and IV

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9. The biomass assimilated by heterotrophic organisms measured in units of mass per unit area

per unit time is

A. gross primary productivity.

B. net primary productivity.

C. carrying capacity.

D. gross secondary productivity.

10. Which of the following statements is correct?

A. A community is a collection of ecosystems sharing similar climatic conditions.

B. A species is a group of organisms of the same population living in the same area at

the same time.

C. Two species of a community may share the same habitat but not the same niche.

D. A population may include two different species living in the same community.

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Section B – Longer answers

11. The graph below shows the density of creosote bushes (Larrea tridentata) plotted

against rainfall in the Mojave Desert in California.

Describe and explain the trend shown in the graph. [4 marks]

density of bushes varies from less than 1 to 5 per 100m2;

density increases with rainfall / shows a positive correlation with rainfall / is directly

proportional to rainfall;

there is likely to be severe competition for water between plants in a desert region;

(E)

rainfall/water is a limiting factor; (E)

hence low density in areas on lowest rainfall; (E)

the correlation is not exact / considerable scatter in data;

there is one anomalous point/outlier;

other factors e.g. production of growth inhibiting toxins / spread of roots / soil type

may reduce/increase density; (E)

possibility of human activities having an effect/clearing/burning; (E) [4 max]

Any other reasonable answer.

Must have at least one “explain” point (E) for full *4+ marks.

Summer 2009 paper2 question 3

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12. a) Name and briefly describe an ecosystem that you have studied. [1]

b) Name three abiotic factors that are important in this ecosystem. [1]

c) For one of these abiotic factors explain how it may affect the abundance of a

named organism that is found in the ecosystem. [2]

d) Explain how a named biotic factor other than human activity might affect the

abundance of the organism named in 12 (c). [2]

(a) Allow [1] for an actual name (toponym) or reasonable location and brief description.

e.g. Wytham Wood, Oxford, UK, mixed deciduous woodland;

Herdsman Lake, Perth, Western Australia, freshwater lake surrounded by

swampland;

small secondary woodlot near Woodbridge, Connecticut, USA;

“Wood” or “Lake” in “name of country”/“tropical rainforest” without a location is insufficient for

credit.

(b) Award [1] for any three abiotic factors appropriate for the ecosystem selected.

e.g. for Wytham Wood

soil pH / temperature / rainfall / sunshine / aspect;

(c) name of organism e.g. (wood)mice;

affected by rainfall which floods burrows and impedes breeding;

Award [1] for name of organism and [1] for effect of factor.

Reject tree, shrub, bird, fish, and other very generic names.

(d) e.g. predation/competition/disease/parasitism;

(e.g. predation by tawny owls) reduces numbers of mice;

Award [1] for named biotic factor and [1] for effect of factor – direction of change in abundance e.g.

increase/decrease/reduce must be specified.

Summer 2009 paper2 question 5

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13. This table gives a list of energy sources used to generate electricity and their cost per

kilowatt hour.

a) Identify the two energy sources with the average lowest cost in Figure 1, and state one

advantage and one disadvantage of each. [3]

b) Outline two reasons why a country may not use the cheapest energy source to produce

electricity. [2]

c) Suggest two reasons why it is so difficult to persuade people to reduce the amount of

energy that they use. [2]

d) Describe how the second law of thermodynamics applies to environmental systems. [1]

Ecosystems summer 2009 paper 1 question 1

Energy source Advantage Disadvantage

natural gas; plentiful supply at present / cheaper than burning coal or oil;

burning releases carbon dioxide / non renewable;

wind; renewable resource / once turbines built it is cheap;

only available when wind blows / not always near population centres;

Award [1 max] for natural gas/wind.

Award [1] for each pair of correct responses of advantages and/or disadvantages.

Do not credit “cheap” with no qualifier.

Accept any reasonable advantages or disadvantages.

Credit advantages and disadvantages for an incorrect source to avoid error carried forward.

(b) inertia / satisfied with existing system;

country wishes to increase diversity of energy sources;

pressure to meet quotas for renewable energy;

some resources not continuously available;

country does not have that resource e.g. HEP, near sea for wave;

Accept other reasonable responses.

(c) people are selfish / inertia / tragedy of the commons;

people desire a better lifestyle which is equated with wanting more e.g. bigger car /

having a fridge;

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poor design of equipment/buildings e.g. standby on electrical equipment / phantom loads;

education; (do not accept “don’t know better”)

(d) environmental systems increase their disorder / all energy ends up as heat;

environmental systems increase their order so go against the law for a short time;

Do not credit answers which just state the second law without relating it to

environmental systems.

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14. The following two figures show a rocky seashore and the distribution of four species of

animal on the seashore. Mean high water mark represents a high tide and mean low water

mark a low tide. The abundance of each species is shown by the thickness of the bars.

a) Identify one abiotic (physical) factor which changes from mean low water mark to mean

high water mark.[1]

b) Mussels are permanently attached to a rock and feed by filtering small particles of food

out of sea water. Suggest one reason why they are only found in the intertidal zone. [1]

c) Distinguish between the terms herbivory and predation. [2]

d) List the following terms in increasing order of size. [1]

Biome, Ecosystem, Biosphere, Habitat

Ecosystems summer 2009 paper 1 question 2

a) time submerged in sea water decreases / time in air increases / salt water

/slope/gradient / area of beach habitat / exposure to wind / oxygen availability

/temperature / exposure to sun;

b) cannot survive drying out for too long;

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cannot compete with organisms which are always submerged;

are able to close their shells so conserve water/not dessicate, but need water to be able

to feed;

turbulence increases food availability;

Accept other reasonable responses.

c) herbivory: process of an animal eating a plant;

predation: process of an animal eating another animal;

d)

All four in correct order needed for [1] mark.

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15. The graph below shows changes in the sea level on the island of Oahu in the

Hawaiian Islands, Pacific Ocean, over the last century. Zero represents the mean sea level

in 1950.

a) Describe and discuss possible explanations for the shape of the curve in the graph. [6]

b) Identify the years in which the lowest and highest levels were recorded. [1]

c) Describe processes that might be involved in the transfer of phosphorus from the water

of the ocean surrounding a remote island to the soil of that island. [3]

d) State whether a remote oceanic island is an open, closed or isolated system. Explain

your answer. [1]

Summer 2008 paper 2 question 1

a) long-term trend of an apparent rise in sea-level;

approx 12 cm (± 3 cm) rise in about 90 years;

possibly due to greenhouse effect / increase in greenhouse gases in atmosphere

(CO2, CFCs, etc.) / global warming; (E)

greenhouse gases trap heat/impede outgoing radiation; (E)

causing rise in mean temperatures; (E)

and thermal expansion of water of oceans / melting of ice (on land); (E)

alternatively might be due to subsidence of island / collapse of volcanic island

material into exhausted magma chamber;

tectonic movements of sea-floor; (E)

short-term fluctuations also occur;

but over too long a time scale to be seasonal;

approx 5-6 cm on either side of trend;

possibly due to shifts in ocean currents/tidal phenomena/El Niño-like phenomena;

(E)

possibility of errors of measurement; (E)

particularly for older records; (E)

relatively stable period in 1950s;

Any other reasonable point.

Descriptions of the graph [3 max]

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Appropriate explain (E) points [3 max]

b) Lowest: 1909 (allow 1908-1910) and Highest: 1980; (allow 1979-1981)

c) phosphates in water absorbed by phytoplankton;

phytoplankton consumed by zooplankton/small fish;

small fish consumed by larger/carnivorous fish;

fish consumed by seabirds (e.g. gulls, terns, albatross, boobies, gannet

cormorants etc.);

seabirds commonly nest on oceanic islands;

phosphates excreted by young and adult birds (guano);

and leached into soil;

or direct splashing of seawater onto soil / blowing of sea-spray by wind;

sea water/organic debris carried onto shore by high tide;

Any other reasonable suggestion.

Accept in form of diagram.

Must have at least three of the above for 3 max

d) open because it exchanges both matter and energy with its surroundings

OWTTE;

Must have both “open” and the explanation for mark.

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16. a) Name and briefly describe an ecosystem which you have studied.

b) Name an organism from each of the following trophic levels found in this ecosystem.

Producer, Herbivore, Carnivore, Decomposer

[2]

c) Choose one of the organisms named above, and explain how a named abiotic factor

and a named biotic factor might influence the abundance of that organism. [4]

Summer 2008 paper 2 question 2

a) Should have name (toponym), or sufficient detail for the site to be identified. No

separate mark for this, but response must be consistent with ecosystem named.

Example: Chalk grassland with scattered shrubs, Fleam Dyke, Cambridgeshire, UK

Mangrove swamp, (near Derby, Western Australia)

Oakwood, (Wytham, Oxfordshire, UK)

Conifer forest with thick understorey, (Vancouver Island, Canada)

Open savanna with Acacia trees, (Kruger National Park, South Africa)

Coral lagoon, (Cocos Islands, Indian Ocean)

b) Examples of each category must correspond to named ecosystem. Names must be

specific: ‘bird’ or ‘tree’ is unacceptable. Common or scientific names are acceptable.

Example (for Wytham Wood):

Producer: Oak tree

Herbivore: Wood mouse

Carnivore: Tawny owl

Decomposer: Bracket fungus on dead wood.

[1 mark] for each pair; if one given, [0 marks]; if 3 given, [1 mark]

c) One of the organisms named in (a) must be given. No separate mark for the name,

but allow ECF in this section if inappropriate organisms named in (a).

Example: wood mouse.

(i) Abiotic factor:

rainfall;

heavy rain may flood burrows and disrupt breeding; reducing population; [2]

(ii) Biotic factor:

numbers of tawny owls;

heavy predation by owls will reduce wood mouse numbers;

competition between wood mice for food;

if food is short, weaker mice starve, reducing population; [2 max]

Must have name of factor [1] and brief explanation [1] in each case for full

marks.

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17. The table below gives the mean dry weight biomass for the primary producers in

certain ecosystems.

a) Define the term dry weight biomass. [1]

b) For one of the ecosystems listed above, describe and evaluate a method for

obtaining such dry weight biomass data. [4]

c) Name one abiotic factor important in the ecosystem you have selected, and describe

how you would study its variation over time. [3]

d) The sketch below shows four types of termite found in Australia. (Termites are

burrowing, colonial insects.)

List three characteristics displayed by the organisms illustrated above that might be used

to construct a key to assist in identifying termites from the same part of Australia. [3]

Summer 2007 Paper 3 Question A1.

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a) the weight/mass of (organic) material, after the removal of water; [1]

b) Methodology will vary slightly with ecosystem chosen.

Award [1] for each of the following up to [4 max]. Award [3 max] if no

evaluation of (E) points given.

mark out measured area;

select quadrats using an appropriate method;

harvest all plant material within sample area;

air dry / oven dry;

Do not accept ‘burn’

weigh;

ideally take several samples and obtain mean;

problems with very large trees / difficult to harvest / destruction of

ecosystem (E);

problems with estimation of subterranean biomass (especially in forest

ecosystems) (E);

Any other reasonable point [4 max]

Points of methodology inappropriate to selected ecosystem should not be

credited.

Reject any discussion of animals / secondary productivity

c) Methodology will depend on abiotic factor chosen and must be appropriate

to the selected ecosystem.

name of factor (e.g. temperature, rainfall);

Do not accept a biotic factor

brief methodology (e.g. use thermometer/thermograph/rain gauge);

repeat observation under similar conditions regularly over period/day/year;

d) Award [1] for two of the following and [2] for three

presence of wings;

presence of pincers;

steeply curved antennae/feelers;

abdomen more than twice the size of head and thorax / relative size of head,

thorax, abdomen;

horn-like structure on head;

absolute size;

Any other reasonable suggestion

Reject number of legs. All the specimens shown have six, as do almost all

(adult) insects.

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Section C Answer ONE question from this section

18. a) Distinguish between pyramids of numbers and pyramids of biomass, and

outline two consequences of pyramid structure in ecosystems. [4]

b) Evaluate the advantages and disadvantages to ecosystems and societies of banning

the pesticide DDT. [6]

c) With reference to examples other than pesticide use, describe the ways in which

farmers can improve the productivity of their soil, and discuss how the strategies adopted

may differ between technocentric and ecocentric farmers. [8]

Expression of ideas [2]

Summer 2009 paper 2 question 4

(a) Award [2 max].

pyramid of biomass represents the standing stock of each trophic level measured in

units such as grams of biomass or energy per sq m; (units required)

pyramid of numbers represents the number of individuals in each trophic level within

a food chain;

Award [2 max].

pyramid structure of ecosystems means that non-biodegradable toxins can become

concentrated in upper levels;

it also demonstrates why there is a limit to the number of trophic levels that can

be supported;

and why species at the top of the pyramid may be more vulnerable to e.g. hunting; [4 max]

(b) Disadvantages of banning DDT: [3 max]

DDT effectively killed malarial mosquitoes, and since the ban populations of

mosquitoes have increased;

incidence of malaria has increased as a result;

malaria is a disease to which children are particularly vulnerable and has huge

socio-economic implications;

90% of all malaria cases are in Africa, a country least able to deal with the

socio-economic consequences of the disease;

Advantages of banning DDT: [3 max]

environmental side-effects of DDT have been avoided by banning its use;

e.g. DDT is not biodegradable and accumulates in the tissues of living organisms

(bioaccumulation) damaging or even eliminating populations;

e.g. because DDT becomes more concentrated along food chains (bioconcentration)

top carnivores tend to be most affected and these may play a very significant role in

maintaining balance of whole ecosystem;

target insects can develop resistance, but DDT also kills other insects which may be

natural predators of the mosquitoes, so the ban allows natural balance to be restored; [6

max]

(c) Methods for improving productivity of soil:

improving fertility of the soil with (organic fertilizers/manure/chemical) fertilizers;

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reducing losses due to pests/disease with chemical treatments;

improving nitrogen fixation by planting leguminous crops e.g. beans;

reducing loss of nutrients due to soil erosion by terracing fields;

reducing loss of nutrients/topsoil due to wind erosion by planting shelter belts;

avoiding over-intensive farming by allowing fields fallow/rest periods;

avoiding depletion of nutrients by rotating crops;

improving yields through irrigation;

avoiding over-compaction of soil through use of appropriate/low impact technology;

reducing wastage by increasing field size e.g. through removal of hedgerows;

use of GM / Green Revolution crops e.g. higher yielding varieties of rice;

Contrasting approaches of ecocentric and technocentric farmers:

both ecocentric and technocentric farmers might apply fertilizers, but choice of

fertilizer might reflect their values e.g. ecocentric using manure (to work with natural

processes), whereas technocentric might use chemical fertilizers;

technocentrics might favour high tech solutions such as GM crops whereas

ecocentrics might be concerned about the ethical issues of GM;

ecocentrics often express a lack of faith in large scale technology so might oppose

strategies used by agribusiness e.g. high tech irrigation systems; [8 max]

Award credit for any other answers of equivalent validity, relevance and substance.

Award [6 max] if no contrast is made between ecocentric and technocentric farmers.

Allocation of marks can be split flexibly for part (c).

Expression of ideas: [2 max]

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19. a) Describe the requirements for photosynthesis to occur, stating the inputs and

outputs of the process. [5]

b) Describe what is meant by gross primary productivity and explain how this differs

from net primary productivity. [4]

c) Construct a flow diagram to show the movement of energy through an ecosystem

with at least three trophic levels. Label all flows and storages. [8]

Expression of ideas [3]

Summer 2008 paper 2 question 7

a) Requirements for photosynthesis/inputs:

presence of green plants;

containing chlorophyll;

appropriate temperature (usually 0–40ºC);

light energy;

of suitable wavelengths;

carbon dioxide;

water;

Outputs:

oxygen;

organic matter/sugars/carbohydrates;

heat;

stored (chemical) energy/ATP;

A diagram is an acceptable alternative to a description or as an addition to a

description.

Allow [1] for each two correct points from lists above [5 max]

b) gross primary productivity is the total amount of organic material produced / solar

energy/carbon fixed by (green) plants/producers;

per unit area per unit time;

energy stored in the organic matter is released through respiration;

to provide the plant with energy for active/metabolic processes;

net primary productivity is the remaining gain in biomass/energy after this

respiration/ NPP=GPP-R;

NPP is the productivity/energy available to herbivores/next trophic level; [4 max]

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c)

For quality of diagram: [2 max]

neat, clear diagram, using boxes for storages and arrows for flows;

reduction in size of storages/flows, at higher trophic levels, shown by reducing

size of boxes/arrows;

Award [6 max] for correct labeling as follows:

Award [1] for each pair of correct storages from list below: [2 max]

Storages:

primary producers;

primary consumers/herbivores;

secondary consumers/carnivores;

dead organic matter/decomposers;

Award [1] for each correctly labeled flow, shown in correct direction (credit each

label only once): [4 max]

insolation;

feeding;

respiration/heat loss;

death/decomposition; [8 max]

Question clearly asks for a diagram; allow no credit for a written explanation.

Expression of ideas [3 max]

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