Nitrogen gas returns to the
atmosphere by the action of
1. nitrogen fixing
bacteria.
2. denitrifying
bacteria.
3. nitrifying bacteria.
4. nitrate fertilizers.
64%
23%
9%
.
ni
tra
t
e
te
r
ni
tri
fy
in
g
ba
c
ac
te
in
gb
ify
itr
de
n
fe
rti
l
ia
.
r ia
.
ria
te
ba
c
ng
fix
i
en
ni
tro
g
ize
rs
.
5%
The sequence of energy flow through
a food chain is
1. primary
consumers- producers- higher
order consumers.
2. producers- higher order
consumers- primary consumers.
3. higher order consumers- primary
consumers- producers.
4. producers- primary
consumers- higher order
consumers.
In a terrestrial ecosystem, the trophic level that
would contain the largest biomass would be the
1. producers.
2. primary consumers.
3. secondary
consumers.
4. highest order
consumers.
5. decomposers.
70%
13%
s.
po
se
r
om
rd
e
de
c
hi
g
he
s
to
co
ar
y
on
d
se
c
4%
r.
..
ns
...
4%
. ..
co
ns
um
pr
im
ar
y
pr
o
du
ce
r
s.
9%
The study of how living things interact
is called:
Ecosystems
Abiotic factors
Ecology
The Energy Pyramid
52%
39%
En
er
gy
Ec
o
Py
r. .
.
lo
gy
4%
Th
e
Ab
i
ot
ic
fa
c
sy
st
e
to
r
m
...
s
4%
Ec
o
1.
2.
3.
4.
The source of energy for almost all life
on Earth is:
Fungi
Animals
Water
Sunlight
88%
13%
ht
Su
nl
ig
W
at
al
m
An
i
er
0%
s
0%
Fu
ng
i
1.
2.
3.
4.
In an energy pyramid, the bottom level
represents:
Consumers
Producers
Scavengers
Decomposers
88%
8%
4%
ge
ve
n
Sc
a
De
co
m
rs
s
ce
r
Pr
od
u
po
se
rs
0%
s
er
Co
ns
um
1.
2.
3.
4.
An example of a consumer in a pond
ecosystem is:
Water lily
Algae
Reed
Frog
79%
17%
Fr
og
ed
Re
ae
0%
Al
g
er
lil
y
4%
W
at
1.
2.
3.
4.
Which of these food chains is in the
correct order?
80%
fro
g,
...
f..
.
ca
t
ta
i
l,
e,
na
k
rs
at
e
w
ca
t
ta
i
l,
ar
,c
pi
ll
er
8%
4%
ca
te
r..
.
...
8%
ca
t
1. caterpillar, cattail,
frog, water snake
2. cattail, caterpillar,
frog, water snake
3. water snake, frog,
caterpillar, cattail
4. cattail, frog,
caterpillar, water
snake
In an energy pyramid, the lowest level
has:
88%
m
ou
n.
..
th
...
m
sa
th
e
or
e
m
ea
en
er
gy
rg
y
le
ss
e
ne
rg
y
ne
ss
e
4%
th
. ..
4%
th
. ..
4%
le
1. less energy than the
top level
2. less energy than the
second level
3. more energy than
the top level
4. the same amount of
energy as the second
level
A food chains shows:
1. one possible pathway
for energy
2. many possible pathways
for energy
3. the amount of energy
available to a producer
4. the amount of energy
available to a consumer
46%
33%
13%
f.
..
nt
o
am
th
e
ou
am
th
e
ou
nt
o
le
m
an
yp
os
sib
le
po
ss
ib
on
e
f.
..
. ..
p.
..
8%
Decomposers are important to
ecosystems because they:
83%
8%
.. .
lig
ht
ve
rt
co
n
nu
t
ng
e
m
ak
e
sim
pl
e
rie
nt
s..
.
.. .
...
hi
g
ch
a
at
ar
e
8%
0%
th
e
1. are at the highest level of
the energy pyramid
2. change simple compounds
into more complex ones
3. make nutrients available
for producers to reuse
4. convert light energy into
sugars through
photosynthesis
Two examples of decomposers are:
1. fungi and bacteria
2. algae and marine
mammals
3. carnivores and
herbivores
4. ferns and mosses
96%
4%
m
os
s..
.
0%
fe
rn
s
an
d
nd
. ..
or
es
a
ni
v
ca
r
an
d
ae
alg
fu
ng
ia
nd
m
ba
c
ar
t. .
.
i..
.
0%
A caterpillar eats a leaf, and a bird eats the
caterpillar. In this interaction, the bird is a:
Producer
Herbivore
Primary consumer
Secondary
consumer
52%
36%
12%
on
da
ry
c
on
s..
.
. ..
Se
c
co
ns
um
Pr
im
ar
y
vo
re
He
rb
i
ce
r
0%
Pr
od
u
1.
2.
3.
4.
How is a food web model different
from a food chain?
54%
21%
o.
..
n
eb
,a
w
In
a
In
a
w
eb
,e
eb
,a
n
ne
o.
..
r. .
.
13%
w
a
In
In
a
w
eb
,e
ne
r. .
.
1. In a web, energy moves from
an organism to only one other.
2. In a web, energy may move to
many organisms from one.
3. In a web, an organism gets
13%
energy from one source.
4. In a web, an organism receives
less energy than in a chain.
An animal that eats only plants is a:
1. Primary consumer
2. Secondary
consumer
3. Tertiary consumer
4. Primary producer
54%
29%
ce
r
er
8%
ar
y
Pr
im
ry
Te
rti
a
pr
od
u
co
ns
um
er
on
su
m
ry
c
on
da
Se
c
Pr
im
ar
y
co
ns
um
er
8%
A snake that eats an insect-eating frog
is a:
1. Primary consumer
2. Secondary
consumer
3. Tertiary consumer
4. Primary producer
48%
28%
20%
pr
od
u
ar
y
Pr
im
ry
rti
a
Te
c..
.
co
ns
u.
..
on
s..
.
ry
c
on
da
Se
c
Pr
im
ar
y
co
ns
um
. ..
4%
Which of the following is difference between the
nitrogen and carbon cycles?
1. Nitrogen can exist as a solid
but carbon cannot.
2. Carbon is released through
decomposition but
nitrogen is not.
3. Carbon is released through
respiration but nitrogen is
not.
4. Carbon is cycled through
animals but nitrogen is not.
67%
21%
8%
cy
c l.
..
...
Ca
r
bo
n
is
re
le
is
Ca
r
bo
n
is
bo
n
Ca
r
Ni
tro
g
en
ca
n
re
le
e.
..
...
4%
Which of the following makes the
nitrogen cycle unique?
50% 50%
...
re
en
Ni
tro
g
Ni
tro
g
en
is
qu
i
...
al
Ni
tro
g
en
is
on
l
he
st
fo
. ..
0%
y.
..
0%
It
i
1. It is the only nutrient
cycle without a gas
2. Nitrogen is always only
a liquid
3. Nitrogen is found in
plants, animals and the
soil
4. Nitrogen requires
specific bacteria for its
cycle
Which of the following correctly traces the
path of a raindrop through the water
cycle?
1. precipitation, run-off,
evaporation, condensation
2. precipitation,
condensation, run-off,
evaporation
3. precipitation, evaporation,
run-off, condensation
4. precipitation, evaporation,
condensation, run-off
55%
23%
pr
e
c ip
it a
tio
n,
. ..
9%
n,
. ..
pr
e
c ip
it a
tio
n,
. ..
tio
c ip
it a
pr
e
pr
e
c ip
it a
tio
n,
. ..
14%
Which of the following is a way carbon
is added to the atmosphere?
1. Evaporation of water
50%
2. Forest fires
3. Photosynthesis
4. Formation of fossil
fuels
21%
21%
f..
.
is
s
of
io
n
Fo
rm
at
sy
nt
he
s
fir
e
Fo
re
st
Ph
ot
o
Ev
a
po
r
at
io
n
of
...
8%
Why are legumes such as peas and
alfalfa considered good for soil?
tr.
..
Th
ey
ha
ve
ni
es
a
ea
v
Th
ei
rl
b
so
r
ab
Th
ey
0%
...
0%
w
a.
..
va
lu
d
ad
0%
a.
..
0%
Th
ey
1. They add valuable humus
to the soil when they die
and decay.
2. They absorb water and
help control runoff.
3. Their leaves are able to
photosynthesis at a very
high rate.
4. They have nitrogen fixing
bacteria in their roots.
15
Where is the oxygen we breathe
produced?
1. in the rocks
2. by decaying
organisms
3. during
photosynthesis
4. as water evaporates
as
wa
t
er
ev
a
ho
to
sy
.. .
du
rin
0%
po
...
0%
gp
go
r..
by
d
ec
a
yin
ro
c
th
e
in
0%
.
ks
0%
15
Which of the following is a way carbon
dioxide can be removed from the air?
building dams
fertilizing crops
mining coal
planting trees
0%
gt
re
es
oa
l
0%
pl
a
nt
in
gc
in
in
m
izi
ng
cr
. ..
0%
fe
rti
l
ld
in
gd
am
s
0%
bu
i
1.
2.
3.
4.
15