Review Packet #6 - Ecology (Topic 4 all)
1.
Which graph correctly shows the increase in the size of a population during the exponential
growth phase?
B.
A.
Population
size
Population
size
Time
Time
D.
C.
Population
size
Population
size
Time
Time
(Total 1 mark)
2.
What term refers to a community and its abiotic environment?
A.
Biosphere
B.
Ecosystem
C.
Habitat
D.
Niche
(Total 1 mark)
3.
Which organisms externally digest dead organic matter and then absorb the nutrients?
A.
Autotrophs
B.
Detritivores
C.
Heterotrophs
D.
Saprotrophs
(Total 1 mark)
1
4.
What are the two components of an ecosystem?
A.
Community and abiotic environment
B.
Species and habitat
C.
Habitat and abiotic environment
D.
Species and community
(Total 1 mark)
5.
Which of the following statements correctly describes the carrying capacity of an environment?
A.
The maximum rate of population growth for a species
B.
The area of land that can support a defined population of a species
C.
The maximum population of a species that can be sustainably supported by a given
environment
D.
The minimum population of a species that can be sustainably supported by a given
environment
(1)
6.
The diagram below is a simplified version of a food web from Chesapeake Bay. The arrows
indicate the direction of energy flow and the numbers indicate species within the food web.
At which trophic level or levels does species II function?
A.
2nd and 3rd consumer
B.
3rd consumer
C.
3rd and 4th consumer
D.
Producer
(Total 1 mark)
2
7.
If identical batches of plants are grown at different temperatures and then harvested to measure
the increase in biomass, which graph shows the expected relationship between the temperature
and the biomass?
A.
Biomass
B.
Biomass
Temperature
C.
Biomass
Temperature
D. Biomass
Temperature
Temperature
(Total 1 mark)
8.
What is an advantage of estimating plant populations by random sampling using quadrats?
A.
Accurate estimates can be obtained more quickly than if every plant in the population is
counted.
B.
Random samples can be taken from the most convenient parts of the habitat.
C.
Numbers of plants in each quadrat can be estimated quickly.
D.
Marking and recapture of plants is not necessary.
(Total 1 mark)
9.
What permits gel electrophoresis to separate fragments of DNA?
A.
Differences in the sizes of DNA fragments only
B.
The number of negative charges on the fragments only
C.
The net charge (negative or positive) on the fragments only
D.
The size and the net charge (positive or negative) on the fragments
(Total 1 mark)
3
10.
The diagram below is a simplified version of a food web from Chesapeake Bay. The arrows
indicate the direction of energy flow and the numbers indicate species within the food web.
Which of the species feed both as secondary consumers and as tertiary consumers?
A.
I, II and IV only
B.
I, III and V only
C.
I, IV and V only
D.
III, IV and V only
(Total 1 mark)
11.
In the binomial system of nomenclature which two names are used to identify a type of organism?
A.
Family
Species
B.
Genus
Species
C.
Family
Genus
D.
Genus
Order
(Total 1 mark)
12. A randomly selected group of organisms from a family would show more genetic variation than a
randomly selected group from which level of classification?
A.
Phylum
B.
Genus
C.
Order
D.
Class
(Total 1 mark)
4
13.
For the following 10 measurements 4, 5, 5, 6, 6, 6, 6, 7, 7, 8 the mean value is 6. What is the best
estimate of the standard deviation?
A.
8
B.
6
C.
3
D.
1
(Total 1 mark)
14.
Which of the following terms describe(s) species X?
I.
Heterotroph
II.
Primary consumer
III.
Secondary consumer
A.
I and II only
B.
I and III only
C.
II only
D.
I, II, and III
(Total 1 mark)
15.
Which is the best prediction about biomass?
A.
The biomass of X is more than the biomass of W.
B.
The biomass of X is less than the biomass of Y.
C.
The biomass of V + X + Z is equal to the biomass of W.
D.
The biomass of Y is less than the biomass of Z.
(Total 1 mark)
5
16.
What units are used when constructing pyramids of energy?
A.
J
B.
J m–2
C.
J m–2 year–1
D.
J kg–1 m–2 year–1
(Total 1 mark)
17.
Which of the following statements describe a “population”?
A.
All the autotrophs and heterotrophs living in a certain area
B.
Individuals belonging to the same species in a certain area
C.
Two geographically isolated groups belonging to the same species
D.
A group of different species living in the same area at the same time
(Total 1 mark)
18.
Consider the simple food web below.
Q
P
T
R
S
Which organism could be a saprotroph?
A.
P
B.
Q
C.
S
D.
T
(Total 1 mark)
19. What is the initial energy source for all terrestrial communities?
A.
Water
B.
Photosynthesis
C.
Light
D.
Glucose
(Total 1 mark)
6
20. Which factors can cause a decrease in a population?
Emigration
Natality
Immigration
Mortality
A.
Low
High
Low
High
B.
High
Low
High
Low
C.
High
Low
Low
High
D.
Low
High
High
Low
(Total 1 mark)
21.
Which statement about the greenhouse effect is true?
A.
It is a recent phenomenon that started about fifty years ago.
B.
It is a natural phenomenon caused by several gases.
C.
It is a natural phenomenon caused by carbon dioxide.
D.
Human activities are the only cause of the effect.
(Total 1 mark)
22.
What is considered to be a characteristic of the members of a Genus?
A.
They belong to a closed gene pool.
B.
Members can interbreed freely under normal conditions.
C.
They share a common ancestral species.
D.
They are limited to certain geographic areas.
(Total 1 mark)
23.
In ecology, what is meant by the term community?
A.
A group of populations living and interacting in the same area
B.
A group of organisms of the same species living and interacting in the same area
C.
A group of organisms which can interbreed and produce fertile offspring
D.
The environment in which a species normally lives
(Total 1 mark)
24.
If 2 000 000 kJ m–2 yr–1 is available from producers in an ecosystem, how much energy (in kJ m–
2 –1
yr ) is usually available to the tertiary consumers?
A.
200 000
B.
20 000
C.
2000
D.
200
(Total 1 mark)
7
25.
The capture-mark-release-recapture method was used to determine the number of Sandhill Cranes
(Grus canadensis nesiotes), an endangered species of bird, living on an island.
The following data were obtained:



number of Sandhill Cranes initially caught, marked and released = 22
total number of Sandhill Cranes caught in second sample = 14
number of marked Sandhill Cranes in the second sample = 2
What is the population size of the Sandhill Cranes on the island?
A.
77
B.
154
C.
308
D.
616
(Total 1 mark)
26.
In the graph below, what could be causing the population change in the region II  III?
A.
Natality > mortality, immigration = emigration
B.
Natality > mortality, immigration > emigration
C.
Natality > mortality, immigration < emigration
D.
Natality = mortality, immigration < emigration
(Total 1 mark)
27.
What is an ecosystem?
A.
A species and its abiotic environment
B.
A community and its abiotic environment
C.
The habitat where a species lives
D.
A population of organisms in a specific habitat
(Total 1 mark)
8
28.
The diagram below shows a simplified version of the carbon cycle.
CO2 in atmosphere
I
II
Fuels
Plants
Secondary
Consumer
Primary
Consumer
What processes are involved in the transfer of carbon at stages I and II?
I
II
A.
combustion
photosynthesis
B.
photosynthesis
respiration
C.
combustion
respiration
D.
fossilization
respiration
(Total 1 mark)
29.
What name is given to an organism that is able to manufacture its own food from simple chemical
materials?
A.
Heterotroph
B.
Saprotroph
C.
Autotroph
D.
Detritivore
(Total 1 mark)
30.
What is a community?
A.
A group of producers and consumers living and interacting in an area.
B.
A group of species living and interacting in an area.
C.
A group of organisms living and interacting in an area.
D.
A group of populations living and interacting in an area.
(Total 1 mark)
9
31.
Which of the following graphs shows the typical growth of a population?
A.
B.
C.
D.
(Total 1 mark)
32.
What are the main sources of carbon dioxide on earth?
A.
Cellular respiration of consumers, producers and combustion of fossil fuels
B.
Photosynthesis and cellular respiration of consumers
C.
Cellular respiration of producers and combustion of fossil fuels
D.
Photosynthesis and combustion of fossil fuels
(Total 1 mark)
33.
What is a factor that increases the greenhouse effect and what is a consequence of it?
Factor contributing to increases in
the greenhouse effect
Consequence of the increased
greenhouse effect
A.
Increasing global temperatures
Rising sea levels
B.
Rising sea levels
Increasing global temperatures
C.
Increasing global temperatures
Burning fossil fuels to run air conditioning
D.
Increases in air travel
Increasing global temperatures
(Total 1 mark)
10
34.
The binomial name for white clover is Trifolium repens. Which species name indicates the closest
relationship with white clover?
A.
Tetrafolium persimilis
B.
Trifolium bulbosus
C.
Bifolium repens
D.
Unifolium trifolians
(Total 1 mark)
35.
What components are needed to make an ecosystem?
A.
A community and its abiotic environment
B.
A community and its source of energy and nutrients
C.
Producers and consumers only
D.
Producers, consumers and decomposers only
(Total 1 mark)
Short Answer Questions
1.
Compare the roles of Rhizobium and Pseudomonas denitrificans in the nitrogen cycle.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 3 marks)
2.
(a)
State how gross production differs from net production in an ecosystem.
.....................................................................................................................................
.....................................................................................................................................
(1)
11
(b)
State the units that would be used if constructing a pyramid of energy.
.....................................................................................................................................
(1)
(c)
Explain how parasitism differs from mutualism, giving an example of each.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
3.
The total solar energy received by a grassland is 5 × l05 kJ m–2 y–1. The net production of the
grassland is 5 × 102 kJ m–2 y–1 and its gross production is 6 × l02 kJ m–2 y–1. The total energy
passed on to primary consumers is 60 kJ m–2 y–1. Only 10% of this energy is passed on to the
secondary consumers.
(a)
Calculate the energy lost by plant respiration.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
12
(b)
Construct a pyramid of energy for this grassland.
(3)
(Total 5 marks)
4.
(a)
A pine forest has a net production of 42 kJ m–2 year–1. Respiration is 100 kJ m–2 year–1.
Calculate the gross production.
....................................................................................................................................
(1)
(b)
State two difficulties of classifying organisms into trophic levels.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(c)
Explain how living organisms may change the abiotic environment during ecological
succession.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 6 marks)
13
5.
The diagram below shows an ocean food web. The arrows indicate the energy flow.
Bacteria
Nanophytoplankton
Nanozooplankton
Microzooplankton
Macrozooplankton
Phytoplankton
Krill
Small fsh
and squid
Emperor Penguins
Weddell Seal
Ross Seal
Adelie Penguins
Large Fish
Crabeater Seal
Toothed Whales
Leopard Seal
Baleen Whales
[Source: www.ciesin.org/docs/011-558/fig4-3.gif]
(a)
Indicate the three producers of this food web.
....................................................................................................................................
....................................................................................................................................
(1)
14
(b)
Identify the trophic level of each organism named below. On the diagram opposite, mark
clearly the arrows of energy flow that support your choice.
(i)
Macrozooplankton
..........................................................................................................................
(1)
(ii)
Weddell seal
..........................................................................................................................
(1)
(c)
Determine the maximum percentage of energy that may reach emperor penguins from
primary producers.
....................................................................................................................................
....................................................................................................................................
(1)
(d) Explain the possible effects of natural selection within the food web if conditions allowed
for a sudden increase in the small fish populations.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 7 marks)
6.
The diagram below is part of a carbon cycle diagram for an ecosystem in a pond.
15
(a)
State the names of the processes that
(i)
convert carbon dioxide into organic compounds in pond weeds and algae
..........................................................................................................................
(1)
(ii) convert organic compounds in pond weeds, algae and primary consumers into
carbon dioxide.
..........................................................................................................................
(1)
(b) (i)
Draw arrows on the diagram above to show how the saprotrophs obtain carbon.
(1)
(ii) Explain the role of saprotrophs in recycling carbon.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(c)
Draw a box on the diagram in an appropriate position, labelled organic compounds in
secondary consumers. Draw arrows to show the links between secondary consumers and
other parts of the carbon cycle.
(2)
There has been a significant increase in the concentration of carbon dioxide in the Earth’s
atmosphere during the last fifty years.
(d)
(i)
Suggest two reasons for this increase in atmospheric carbon dioxide concentration.
1.
................................................................................................................
..........................................................................................................................
2.
................................................................................................................
..........................................................................................................................
(2)
(ii) Suggest one effect of an increase in carbon dioxide concentration on organisms in a
pond. Include in your answer the reason for the effect and the type of organisms that
are affected.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 11 marks)
16
7.
(a)
Outline why the transparency of water is important to organisms living in an aquatic
habitat.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(2)
(b)
The diagram below shows a simplified food web for a lake.
[Source: Water on the Web (2004), Monitoring Minnesota Lakes on the Internet and Training Water Science
Technicians for the Future – A National On-line Curriculum using Advanced Technologies and Real-Time Data,
www.waterontheweb.org/under/lakeecology/11_foodweb.html,
reprinted with the permission of Water on the Web project, University of Minnesota, Duluth, MN 55812]
(i)
State the initial energy source for the above food web.
.........................................................................................................................
(1)
(ii) Define the term trophic level.
.........................................................................................................................
.........................................................................................................................
(1)
17
(iii)
Deduce the trophic level of the immature game fish.
.........................................................................................................................
(1)
(iv) In the food web shown, identify one heterotroph and one autotroph.
heterotroph: ....................................................................................................
autotroph:
....................................................................................................
(1)
(Total 6 marks)
8.
(a)
The diagram below represents a pyramid of energy for a community of organisms. State
what the bars labelled I and II indicate.
I
Trophic
level
II
Energy flow / kJm –2 y –1
I.
.........................................................................................................................
II.
.........................................................................................................................
(2)
(b) Define the term biomass.
...................................................................................................................................
...................................................................................................................................
(1)
(Total 3 marks)
18
9.
(a)
Outline the use of a biotic index in identifying environmental change.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(4)
(b)
Discuss the relationship between CFCs and the hole in the ozone layer.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(6)
(Total 10 marks)
19
10.
Describe the causes and effects of the increased greenhouse effect.
(Total 6 marks)
11.
Discuss reasons why the biodiversity of rainforests should be conserved.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 7 marks)
20