Biology 612 Freshwater Biology Fall 2012 Exam 1
Name______________________
1. Why do both human population growth and increasing affluence (standard of living)
mean that freshwater resources will come under greater stress in the future? (5)
2. Describe how a swimming bacterium experiences swimming in water relative to a large
fish with respect to turbulence, streamlining, the effect of a wall, viscosity, and inertia (5)
3. Describe 3 major ways that lakes form, and what you expect their relative age to be for
each cause of formation (6)
4. Fill in the following table on properties of water (10)
Property
Aspect
Causes water to assume a crystal shape upon
freezing and many other water properties
Temperature of maximum density
Causes water to creep up fine tube
Viscosity as temperature increases
Relative amount of salt dissolved as
temperature increases
Relative amount of gas dissolved as
temperature increases
Density of solid phase relative to liquid phase
Relative density as dissolved salt increases
buffers water against rapid changes in
temperature
Effect of 5 degree C increase from 5 to 10
relative to that from 20 to 25 degrees C
5. How do the physical characteristics of a reservoir vary from that of most natural lakes?
List 5 aspects. (5)
6. Josh Perkin talked about how the dewatering of streams can cause fragmentation of
stream networks. What life history reproductive tactic of some fish species (e.g. the
plains minnow) is particularly sensitive to this dewatering? (5)
7. What did James Whitney talk about (in a couple sentences) with respect to the Colorado
River fish communities (5)?
8. Wetlands were formerly thought to be useless, but we now know wetlands provide some
essential ecosystem goods and services to people. List 4 of those services (4).
9. What does the urbanization of watersheds do to peak discharge of floods and how would
this influence: (a) erosion rates, (b) the average size of particle that moves downstream,
and (c) the rate of meander formation ? (6)
10. Why is the biological species definition not useful many of the species we study as
aquatic ecologists (3)?
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11. Why are ribosomal RNA (rRNA) sequences useful taxonomic tools for determining large
differences between organisms (i.e. long periods of evolutionary separation), as well as
differences between closely related species? (5)
12. Match the terms with the letters (20)
Dimictic
Hypolimnion
Epilithic
Archaea
Exploitation
Mutualism
Emergent
A.
B.
C.
D.
E.
F.
G.
Chemoautotrophic
Heterotrophic
H.
I.
Seiche
Langmuir circulation
J.
K.
Fetch
L.
Monomictic
M.
2nd order stream
Thalweg
Everglades
Karst
N.
O.
P.
Q.
Blue light
Water table
R.
S.
Light attenuation
T.
forms when 2 first order streams join
mixing twice a year
fastest flowing portion of lake or river
self feeding using chemicals
causes streaks on lakes
mixing once a year
managers trying to save by diverting
water flow back into this large wetland
+/+ interaction between species
rugged landscape formed by limestone
dissolution
growing on rocks
transmitted more readily in pure water
than red light
must get carbon from organic carbon
sources
Where aquifer meets vadose zone or
surface
bottom of a stratified lake
Growing out of the water
one of the three domains of life
generally logarithmic loss with depth in
lake
rocking of water in lake
Distance across which water acts on a
lake
+/- interaction between two species
13. Fill in the blanks in the sentences (10). Molecular diffusion is slower than
_____________ diffusion. Mixing causes this type of diffusion, but such mixing does not
occur in the ___________ zone very close to solid surfaces. As geometric objects get
larger their surface __________ to ____________ ratios get smaller, leading to diffusion
limitations. Larger multicellular organisms cannot move materials into their cells quickly
enough with molecular diffusion so they have _____________ systems that help
overcome diffusion limitation. Other factors that influence diffusion rates include
temperature (with _________ rates of diffusion at higher temperatures), concentration (
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with ____________ rates of diffusion with greater differences in concentration) and
distance ( with _____________ rates of diffusion with greater distances between two
points). Fine sediments have lower diffusion rates of materials through them than coarser
gravel because __________ number is smaller, with _____________ viscosity because of
small distances between particles.
14. Fill in more blanks (11). Cyanobacteria are bacteria, not _____________. They grow in
nutrient rich water and are problematic because they can be ________________ and also
can make water unfit to drink because of ____________ and odor problems. They can
synthesize at least two forms of toxins, ____________ and ____________. They do well
in low light because they have special pigments that absorb in the green region, unlike
eukaryotic algae that mainly use _______________ for light absorption. They are also
successful because they synthesize gas vesicles that make them __________ dense than
water and allow them to float. These floating scums are not pleasant and can
___________ property values of lake-front properties. They are unlike diatoms, in part,
because they do not have a cell wall made of _____________. The cell wall of diatoms is
used in forensics to help confirm victims of _______________. If cells of either of these
groups are found on the bottom, they are referred to as benthic, if they are suspended they
are referred to as ________________.
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Freshwater Ecology Biol 612 2nd Midterm Fall 2012
____________________Name
1. Draw the nitrogen cycle as presented in class and in the book (20)
2. Draw the carbon cycle as presented in class and in the book (20)
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3. Match letter on right with term on left (20)
Trichoptera
Epemeroptera
Plecoptera
Sponge
Unionid mussels
Daphnia
Copepoda
Zebra mussel
alpha diversity α
beta diversity β
eveness
redox
Amphipoda
Isopoda
Geologically old lakes
large area versus small area habitat
sulfate
conductivity
pH
higher altitude
A. Cladocera
B. dorsal-ventrally flattened crustacean
C. Mostly marine group with silica spicules but
some species in fresh waters
D. juvenile naupliar stages
E. the relative number of free electrons in a
solution
F. laterally flattened crustacean
G. more diversity expected
H. stone fly
I. can serve as an electron acceptor for anaerobic
respiration
J. diversity among habitats
K. Caddis fly
L. Introduced to great lakes in ship ballast
M. saturation concentration of dissolved oxygen
lower
N. Endangered group, formerly used to make
buttons
O. a measure of the degree of equal distribution of
numbers of each species in a community
P. a measure of the number of dissolved ions in
solution
Q. negative log to base 10 of hydrogen ion
concentration
R. High degree of endemism
S. within habitat diversity
T. Mayfly
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4. Amphibians are threatened by pollution and several other factors that are leading to their
extinction around the globe. What are some of the other factors leading to the loss of
species and what is it about amphibian life cycles that make them particularly susceptible
to pollutants? (4)
5. Describe how nucleic acids (DNA and RNA), lipids, and proteins are altered in
organisms that can withstand very high temperatures (6)
6. Why do depths of saline lakes typically fluctuate widely over years? (4)
7. Humans are causing the 6th great extinction on Earth, with probably half the species
disappearing in your life time. Why does diversity matter to humanity? (5)
8. If you dumped a whole bunch of iron into a lake, what would you expect to happen to the
concentrations of phosphate and sulfate? (4)
9. Why are deep groundwaters harsh habitats? (4)
10. What caused the disaster at Lake Nyos? (4)
11. Describe the difference between net and gross primary production and how they are
related to respiration? You can do this verbally or with an equation (5)
12. Give the equations for photosynthesis and respiration (4)
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Biol 612 Freshwater Ecology 3rd Midterm 2012
Name___________________
1. Match the terms (20)
Term
Chronic
Match
A. Increase in concentration from
environment into a single organism
B. Greater aluminum solubility
C. Growth as a function of external
nutrient concentration
D. Growth as a function of intracellular
nutrient concentration
E. 106:16:1 C:N:P
F. More nutrient rich than mesotrophic
G. Following magnetic lines to find
sediment
H. Using organism remains in sediments
of lakes to infer past environmental
conditions
I. CH2O + O2 → CO2 + H2O+ chemical
energy
J. Using organisms present to indicate
state of environment
K. Uptake as a function of external
concentration
L. Search strategy
M. Pulsed exposure
N. Can be used as food web tracer
O. Hormone mimics that are active at low
concentration and influence
development
P. Macrophyte removal
Q. Long term
R. Can cause decreased diversity in urban
areas
S. CO2 + H2O + light → CH2O + O2
T. Increase of concentration through the
food web
Acute
Bioconcentration
Biomagnification
Bioassessment
Ecoestrogens
Paleolimnology
Increased fish mortality with lower pH
Road salt
Monod equation
Michaelis-Menten equation
Droop equation
Redfield ratio
Hypertrophic
Grass carp
Photosynthesis
Respiration
Random walk
Magnetotaxis
Stable isotopes of C and N
2. Suspended solids can be thought of as a pollutant, but they are a natural part of many
ecosystems. Under what conditions do you think sediments should be defined as a
pollutant, and what types of particulate materials might be beneficial to river and stream
organisms? (5)
6
12
10
8
6
4
2
0
ingestion rate
Filtering rate
3. What are the EC50 and LD50 , and which one is generally lower and why? (5)
4. Why is nutrient concentration not necessarily the best index of nutrient availability to
satisfy demand? (5)
5. Why was eutrophication reversible in Lake Washington, but not in Lake Trummen? (5)
6. List 5 ways that aquatic prey have evolved to avoid predation, and potential non-lethal
implications (evolutionary costs) of each (5)
7. Why is a “two story” fishery threatened by eutrophication? (5)
8. Why might the trophic cascade not apply to the microbial loop? (5)
9. We have a stream that has completely dried, and now just started flowing. What types of
organisms might show up first and what might end up there last over the next six months?
What life history characteristics are mostly likely to be associated with the first versus the
last organisms (6)?
10. Describe the seasonal succession in a temperate oligotrophic lake with respect to
phosphorus, silica, diatoms, cyanobacteria, phytoplankton, zooplankton, and larval fish.
You can use a series of graphs or words (7)
11. Fill in the following graphs for Daphnia feeding on different concentrations of algae (one
line each) (6)
0
0.5
1
15
10
5
0
0
1.5
0.5
1
1.5
Algal cells per uL
Algal cells per uL
12. Fill in the blanks: Species_____________ will win at high SiO4 and low PO4 species,
and Species ______ will win at low SiO4 and low PO4 and they will ____________
_______ (6)
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13. Give some reasons why top down control of eutrophication might fail to lower algae in
the in a short term and long term management plan (5).
14. List 5 potential negative consequences of non-native fish species introductions (5)
15. List 3 problems that are endangering the Everglades in Florida (3)
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Biology 612 Final Fall 2012
name_________________________
1. Describe how a reservoir might disrupt the natural sequence of a river continuum (5)
2. Indicate , high (H) medium (M) or low (L) , how the habitats rank on the following
abiotic and biotic scales. See first line for example (5)
Feature
Deep groundwater
Light
L
Hydrologic
turnover time
Seasonal variance
Allochthonous C
inputs
Terrestrial input
Importance
photosynthesis
Lake
H
Small Stream
M
3. Describe the concept of nutrient spiraling and how temperature and water velocity might
be related to spiral length (5)
4. Match the material (25)
Item
Phytoplankton
zooplankton
benthic
Related
A. On the bottom
B. Macrophyte removal
C. Effect of top predator on primary
producer
D. Without dissolved oxygen
E. Low Reynolds number
F. One of three domains of life
G. Suspended producers
H. Between habitats
I. Mineralization/ remineralization
J. Area above groundwater
K. Grabben and horst
L. Carbon flux through microbial
component of food web
M. More intense runoff
N. Suspended animals
O. Increase in toxin moving up the food
web
P. Ephemeroptera
Q. Silicon cell wall (frustule)
R. Both species benefit
S. Organism colonization in new habitat
mutualism
photoinhibition
Cyanobacteria
Mayfly
Caddisfly
Nutrient supply source
Diatom
Tectonic lake
Net primary production
Biomagnification
Redfield ratio
Asian carp
Primary succession
Trophic cascade
Microbial loop
Anoxic
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Light attenuation
High viscosity
Beta diversity
Vadose zone
Urbanization
Archaea
T.
U.
V.
W.
X.
Y.
Logarithmic with depth
High light
Trichoptera
Gross primary production - respiration
106:16:1 C:N:P
Nitrogen fixing heterocysts
5. Diagram and label the nitrogen cycle as it was done in class (10)
6. Describe the seasonal pattern of lake stratification in a temperate deep lake, and what
causes it to form and mix and when (5)
7. The trophic cascade has been linked to deeper epilimnion because it clears the water
column of algae, why might this happen? (5)
8. List 5 values of ecosystem goods and services and how lake eutrophication might harm
each one of them (10)
9. Fill in the following table by circling one of the two words in each cell of the right
column (10)
Property
Reynolds number when water flows through fine sediments relative to
coarse sediment
Viscosity of water trying to filter bacteria as opposed to trying to filter
larger algae
Need to streamline for large swimming organisms compared to small
ones (e.g. trout vs bacterium)
Inertial of large swimming organisms compared to small ones (e.g.
trout vs bacterium)
Viscosity of cold water compared to warm water
Surface area to volume ratio of small sphere compared to large sphere
Rate of diffusion cause by molecular diffusion relative to turbulent
flow (eddy diffusion)
Light attenuation in a eutrophic versus an oligotrophic lake
Attenuation of blue light relative to red light in an oligotrophic lake
Density of ice compared to liquid water
Relative amount or
magnitude
Larger smaller
Greater Less
More Less
Greater Less
Greater Less
Greater Less
Greater Less
Greater Less
Greater Less
Greater Less
10. Why is it more difficult to reverse eutrophication once oxygen disappears from the
hypolimmion as a lake becomes more eutrophic? (5)
11. List at least one author of the textbook for the class(5), if you get both then 2 points extra
credit
12. What are the major goals of sewage treatment plants and how do they accomplish those
goals? (10)
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