Semester 2 Exam - Review Questions Topic 2

Topic 2 The EcosystemNotes Ch. 2 Part 1

2.1 Structure pp. 14 - 23

IB1. Which list contains only abiotic components of an ecosystem? A. air, water, rock B. air, producers, climate C. soil, consumers, water D. carnivores, herbivores, decomposers

IB2. Which list includes three abiotic factors that affect aquatic plants? A. number of decomposers, pH of water, day lengthB. water temperature, oxygen concentration, light intensity C. carbon dioxide concentration, number of primary consumers, wavelength of light D. water temperature, number of secondary consumers, carbon dioxide concentration

IB3. Most food chains seldom have more than four trophic levels because

A. in most ecosystems, competition for food is very great. B. the total biodiversity in any ecosystem is limited. C. energy is lost as it moves along a food chain and little remains at the level of the top carnivore. D. in many parts of the world, many species have become extinct and complex ecosystems are rare.

IB4.

The diagram below represents the pyramid of biomass for a certain ecosystem.

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The most likely explanation for the biomass of trophic level 2 being greater than that of trophic level 1 is that the

A. system shows seasonal fluctuations and the plants have died off before the herbivores.

B. number of plants is greater than the number of herbivores.

C. number of herbivores is greater than the number of plants.

D. productivity of the herbivores is greater than the productivity of the plants.

IB6. An ecological niche is A. where a species lives. B. all the populations of an ecosystem. C. what a species eats.D. the role a species has in an ecosystem.

IB8. A community is composed of A. several habitats. B. several populations.C. several abiotic factors. D. biotic and abiotic factors

IB9. Which interaction would benefit both organisms in a relationship? A. Predation B. Commensalism C. Mutualism D. Competition

IB10. Spiders mainly use a web and poisonous fangs to trap and eat insects such as flies. What type of interaction is this? A. Parasitism

tro p h ic le v e l 3

tro p h ic le v e l 2

tro p h ic le v e l 1

ca rn iv o re s

h e rb iv o re s

p ro d u c e rs

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B. Competition C. Mutualism D. Predation

2.2Measuring abiotic components pp. 24 – 28

IB11. Which list contains only abiotic factors in a marine environment? A. algae, temperature and nitrogen level B. salinity, turbidity and plankton C. decomposers, carbon dioxide and calcium level D. pH, dissolved oxygen and light intensity

IB12. Which of the following is a list of abiotic factors that affect the distribution of organisms? A. Sunlight, decomposers and soil pH B. Temperature, sunlight and soil pH C. Water, sunlight and competition D. Disease, pH and dissolved oxygen

Below is a diagram of part of a food web.

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Which of the following is an abiotic factor that might affect this food web?

A. Presence of parasites

B. Spread of diseases in frogs

C. Increase in temperature

D. Introduction of new plant species

2.3 Measuring abiotic components pp. 29 – 35

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in sec ts

g ree n p la n ts

sn a ils

fro g s

sn ak es

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The table below gives the number of individuals of four species of trees in two small patches of Australian forest.

Tree species Area A Area B

Allocasurina huegelina 4 1

Banksia grandis 5 8

Eucalyptus calophylla 7 9

Acacia saligna 4 2

______________________________________________________________

(b) (i) Using the formula for Simpson’s diversity index

D =

calculate which of area A or area B has the higher diversity index. Show your working.

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Topic 2 The EcosystemNotes Ch. 2 Part 2

2.4 Biomes pp. 35 – 43

1. Define biome :.2. According to fig. 2.17 what are the two major climatic factors that affect biome or

ecosystem distribution?

3. In general , fig. 2.18 show what type of weather do you get with low pressure zone? High pressure zones?

4. The pressure at the equator is _________ causing _________ rain fall typical of tropical rainforests.

5. The pressure at 300 N and S of the equator is generally ___________ causing ________ rain fall typical of deserts.

6. _________ pressure occurs again at 600 N and S causing _________ rain fall typical of temperate forests.

7. Define insolation - 8. Define NPP –

QUESTIONS

IB1 What is a biome?

A. A collection of ecosystems sharing similar climatic conditions

B. A group of populations living and interacting with each other in a common habitat

C. A community of independent organisms and the physical environment they inhabit

D. A group of organisms that interbreed and produce fertile offspring

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IB2 Which biome is usually found adjacent to ice-caps?

A. Tundra

B. Grassland

C. Tropical rain forest

D. Temperate forest

IB3The main deserts of the world are found at

A. latitudes between the tundra and temperate forests.

B. lower latitudes than temperate and tropical forests.

C. latitudes between the temperate and tropical forests.

D. higher latitudes than the tundra.

IB4 Major climatic factors affecting ecosystems are

A. temperature and precipitation.

B. temperature and salinity.

C. ocean and air currents.

D. Rossby waves and Hadley cells.

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IB5 The graph below shows net primary productivity (NPP) of eight major biomes.

[D Waugh, Geography An Integrated Approach, (Nelson Thornes Ltd., 2000) p. 304.Reproduced by permission of Nelson Thornes Ltd.]

(a) (i) Compare, and give reasons for, the differences in net primary productivity between any two biomes named in the graph.

(4)

(ii) State two of the main factors which influence productivity.

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5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

Net

prim

ary

prod

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ity /

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–2–1

Trop ica l ra in fo re s ts

D ec id u o u sfo re s ts

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Tem p era te g ra sslan d s

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2.4 Function pp. 43- 55

Carbon Cycle

Nitrogen Cycle

Water Cycle

Questions

IB6 Nitrogen is returned to the atmosphere by

A. lightning discharges.

B. denitrifying bacteria.

C. nitrifying bacteria.

D. leguminous plants.

IB 7 Below is the diagram of the nitrogen cycle.

O rg an icre s id u es

A n im als

P lan ts

A tm o sp h ericn itro gen

N itra te io n s

N itrite io n s

A m m o n iu mio n s

I

IIIII

IV

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Denitrification is

A. I.

B. II.

C. III.

D. IV.

GP, GPP, GSP, NP, NPP, NSP pp. 52-53

Questions

IB 9 Net Primary Productivity (NPP) is the total amount of energy fixed in an ecosystem by

A. photosynthesis minus the amount used by producers and consumers in respiration.

B. photosynthesis.

C. photosynthesis minus the amount used by producers in respiration.

D. herbivores.

IB 10 If the rates of photosynthesis and respiration (in a plant) were exactly equal, which of the following would be true?

A. Net Productivity would equal respiration

B. Net Productivity is at a maximum

C. Net Productivity would equal Gross Productivity

D. Net Productivity would be zero

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IB 11 The diagram below shows the flow of energy through a food web.

Gross Primary Productivity (GPP) is

A. b – c

B. b – (a + c.)

C. b.

D. b – c – d.

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Topic 2 The EcosystemNotes Ch. 2 Part 3

2.6- Changes pp. 55-72

IB 1 The carrying capacity of an environment for a given species

A. can never be exceeded. – not true : overshoot and die back

B. is greater for a population with a slow reproductive rate. – greater for populations with high reproductive rates

C. is achieved when birth rates equal death rates.- when death rates increase and birth rates decrease overall but not only when death rates = birth rates

D. can only be exceeded with unsustainable use of resources. - true

IB 2 The main difference between ‘S’ and ‘J’ population growth curves is that

A. ‘S’ curves demonstrate exponential growth.

B. ‘J’ curves demonstrate exponential growth.

C. ‘S’ curves reach no stable maximum.

D. ‘J’ curves reach no stable maximum.

IB 3 As disease spreads through a population, numbers fall. As the result of a reduction in contact between individuals, the rate of spread of the disease is reduced. This is followed by a recovery in numbers.

This is an example of

A. positive feedback

B. negative feedback

C. demographic transition

D. entropy

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IB 4 A parasite, infecting the organs of its host, spreads from host to host more rapidly when the host population, in a given area, is higher. Assuming infection with the parasite reduces fertility, this would be an example of control of the host population through.

A. an external, density independent factor.

B. an internal, density dependent factor.

C. an external, density dependent factor.

D. an internal, density independent factor.

IB 5 Which statement most correctly describes K-strategist organisms?

A. They reach adulthood quickly and have many young.

B. They reach adulthood slowly and have many young.

C. They reach adulthood quickly and have few young.

D. They reach adulthood slowly and have few young.

IB 6 (a) Explain what is meant by the terms ecological succession, pioneer community and climax community.

(6)

(b) For a named ecosystem, describe how the abundance of the different species of organisms present changes during the various stages of succession.

(5)

(c) Describe and explain how gross primary productivity changes during the stages of succession.

(6)

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IB 7 In the process of succession, earlier communities disappear because

A. they are displaced through competition.

B. their gross productivity decreases with age.

C. they eventually produce disadvantageous changes to their physical environment.

D. their biodiversity is low.

IB 8 Ecological succession generally involves

I. a decrease in the entropy of an ecosystem.

II. loss of communities through competition.

III. an increase in the ratio of organic to inorganic storages.

A. III only

B. I and II only

C. II and III only

D. I, II and III

IB 9 In the process of succession, earlier communities disappear because

A. they are displaced through competition.

B. their gross productivity decreases with age.

C. they eventually produce disadvantageous changes to their physical environment.

D. their biodiversity is low.

IB 10 Ecological succession generally involves

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I. a decrease in the entropy of an ecosystem.

II. loss of communities through competition.

III. an increase in the ratio of organic to inorganic storages.

A. III only

B. I and II only

C. II and III only

D. I, II and III

IB 11 Compared to pioneer communities, climax communities usually have

A. a higher net productivity.

B. a higher gross productivity.

C. inverted pyramids of biomass.

D. shorter food chains

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2.7- Measuring Changes along an ecological gradient pp. 73-74

a) Define each of the following:

1. Ecological gradient - 2. Quadrat method - 3. Line transect – 4. belt transect – 5. continuous transect - 6. interrupted transect –.

b) Explain fig. 2.56

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