5. (a)
(b)
6. (a)
(b)
Explain the term biomagnification
($
bioamplication).
non-biodegradable insecticide used to kill insects. Explain why the consumers
at
the top level of a food chain has the highest concentration of this insecticide.
occupied
DDT is
a
What is environmental biotechnology?
Explain the process of treating sewage using environment biotechnology in water reclamation
plants.
Topical Practice Questions
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d
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Danyal Education
Organisms and their Environment Assignment 1
Section A: Multiple-Choice Questions
1.
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The diagram below shows part of a woodland food web.
kestrels
,/\
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a
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bank
voles
t
grass
n
a
WTENS
/\
goldfinches
aphids
t
t
hogweed
ivy
caterpillars
oak tree
C
Which one of the following would you expect to find in the largest numbers in the food web?
A caterpillars B goldfinches C
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Which of the following groups of organisms are decomposers in an ecosystem?
2
A
water
fleas
B caterpillars C bacteria
D
vultures
The table shows the amount of energy flowing into four trophic levels in an ecosystem. Which letter
represents the producers?
r-..-,
A4
B45
c
D
4.
n
energy flowing in/kJ
per m2 per year
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3.
4000
Study the food chain below.
grass -+ caterpillar -+ sparrow -+ hawk
An insecticide was sprayed to kill the caterpillars. ln which organisms would the highest level of
insecticide accumulate after a period of time?
A hawk
B sparrow
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C caterpillar D
grass
A river has been polluted by sewage. Compared with unpolluted water, the water in this river will
5
have
B
D
more fish.
more oxygen
Section B: Short Answer Questions
1.
fewer bacteria.
Ed
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C
more nitrogenous compounds.
The food web below shows the relationship between some organisms in a woodland community.
al
eagle
owl
t
m0ng00se
sparrow
,/
shrew
ny
,,
/_----*
insect
e \
caterpillar
grasses
1
snake
field mouse
\
,r'
rabbit
7
young shoots
(a) Name a primary consumer
Da
[1m]
(b) (i)
Select a food chain consisting of four organisms from the above food web. By means of
a diagram, show the relative total energy of the organisms in the food chain you have
selected.
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(ii)
(c)
Explain your diagram in terms of the energy flow in the ecosystem.
[2m]
Describe the consequences that myxomatosis (a disease fatal to rabbits) might have on allthe
web.
[5m]
(d)
Supposing all the snakes and rabbits were removed from the community, explain what you
would expect in the population size of the eagle after the following time frames:
(i) two months
[1mj
[1m]
How is a food chain different from a food web?
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(e)
two years
Ed
(ii)
Some students carried out a study on an ecological habitat and they gathered the following data.
ny
2.
uc
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organisms in the food
Da
'Water fleas fed on green algae and protozoa. Protozoa fed on green algae. Many small fish were
seen and they fed on water fleas, tadpoles and mosquito laruae. Tadpoles fed on water fleas,
protozoa and green algae. They grew into large frogs after some time. Mosquito larvae fed on green
algae. We could not see any rnosquifoes though.'
(a) Suggest a name for the ecosystem
(b)
the students were studying
State the two types of relationship that exist between the tadpoles and water
[1m]
fleas.
[2m]
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(c)
Construct a food web from the above information
(d)
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[3m]
From the food web you constructed in question 2(c), name an example of each of the
following:
(i) Producer
Primary consumer
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[2m]
(iii) Secondaryconsumer
Omnivore
Da
(iv)
(e) State three ways in which humans might affect the balance of plants and animals in the habitat
above.
[3m]
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3.
The diagram below shows the carbon cycle in nature
dead bodies
/
C
fuels
protoplasm
in animals
D
a
B
dioxide+-
--------'
A
(a)
Name the processes A
-
F.
A
[3m]
B
D
C
F
E
State two human activities not mentioned in the diagram that would disrupt the carbon cycle.
Explain how these two activities disrupt the carbon
[2m]
cycle.
Ed
(b)
protoplasm
in plants
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carbon
Section C: Free Response Questions
1. (a) Construct a food web with the following organisms associated
community.
algae
water snail
shrimp
smallfish
mosquito larva
water lily
protozoa
plankton
al
kingfisher
large fish
With the help of your food web, explain how carbon is used continuously in nature. [5m]
Using named examples, explain how human activities may affect a food chain, and the possible
consequences of this
[3m]
action.
Da
ny
(b)
(c)
with a freshwater pond
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