BIOL 473 FINAL UPDATED ACTUAL
Exam Questions and CORRECT Answers
Functional Response - CORRECT ANSWER - relationship between prey density and the
feeding rate of a predator
Sediment microzone - CORRECT ANSWER - zone of oxygenated sediments around the
roots of macrophytes
hyporheic zone - CORRECT ANSWER - subsurface habitat of streams/rivers where
ground water mixes with surface water
Cyclomorphosis - CORRECT ANSWER - phenomenon seen in zooplankton where their
morphology changes in response to predation pressure/presence.
tephra - CORRECT ANSWER - obvious band found in sediments produced by volcanic
ash
Riparian habitat - CORRECT ANSWER - habitat forming the boundary between
terrestrial and aquatic ecosystems
redox potential - CORRECT ANSWER - environmental conditions that control the
tendency for oxidizing or reducing chemical reactions to proceed (controlled mostly by oxygen [
])
True or False
1. most of the worlds available freshwater is found in large rivers
2. floods often increase the productivity of river food webs
3. stream order is used to describe a hierarchy of water clarity in streams
4. winterkill threatens only warm-water fishes in lakes that freeze
,5.acid rain was once a risk to all lakes in north America but conditions have improved recently
6. the paradox of the plankton questions why so many zooplankton species can coexist w high
densities of planktivorous fish
7. rotifers swim under the influence of very low Reynolds numbers
8. the N:P ratio of nutrients available to phytoplankton can regulate the types of phytoplankton
found in lakes
9.eutrophication of lakes and rivers can result from industrial-scale agriculture
10. rotifers are the only major zooplankton group that produces fossils that can be used in
paleolimnological studies
11. most of the CO2 that is release - CORRECT ANSWER - 1. false
2. true
3. false
4. false
5.false (not to all lakes)
6. false
7. true
8.true
9. true
10.false
11. false
12. false
13. true
How has climate warming during the last 50 years changed seasonal water flows in streams of
the PNW - CORRECT ANSWER - - lower snow pack (interferes with fresh water supply)
- reducing summer flows
- earlier spring flow (changes in precipitation density)
- earlier center-of-mass of seasonal stream flow timing (causes a surge of flooding at less
predictable times of year)
-warming lakes
, - shrinking glaciers
-trend towards warmer air temps
5 different variables that can be used in paleolimnological studies of lakes, and what they are an
indicator of - CORRECT ANSWER - 1. diatom: pH
2. sponge spicules: lake silica concentration
3. algal pigments: phytoplankton
4. N isotopes: Salon density
5. pollen: plants in wateshed
describe how the type of macrophytes found in littoral habitats changes along the depth gradient
in lakes - CORRECT ANSWER - - emergents found in shallow water, then floating, then
submergents in deepest water.
- gradient explained by the energy/resources allocated to stems vs leaves. In deep water,
producing really long stems is too expensive
Briefly describe how spawning populations of Pacific salmon affect biological, physical and
chemical processes in aquatic and riparian habitats in the Pacific Northwest and Alaska. Why
might these "salmon effects" be greater than the effects of the resident fishes in lakes and
streams? - CORRECT ANSWER - - the effects of salmon are greater than for resident
fishes b/c they come back w alot of energy and nutrients from the ocean
- biologically salmon are a source of food for lots of consumers
- chemically they are a source of nutrients (N and P)
- physically they are a source of disturbance that dislodges sediments or causes ecosystem
engineering.
Briefly describe why the processes of biomagnification and bioaccumulation lead to high PCB
concentrations in birds that prey on fishes - CORRECT ANSWER - - bioaccumulation is
the process where an organism can consume more contaminants than it can excrete , therefore its
concentrations are higher than water
- in biomagnification, you get successive jumps in contaminant concentration as you move up
through trophic position in a food chain
Exam Questions and CORRECT Answers
Functional Response - CORRECT ANSWER - relationship between prey density and the
feeding rate of a predator
Sediment microzone - CORRECT ANSWER - zone of oxygenated sediments around the
roots of macrophytes
hyporheic zone - CORRECT ANSWER - subsurface habitat of streams/rivers where
ground water mixes with surface water
Cyclomorphosis - CORRECT ANSWER - phenomenon seen in zooplankton where their
morphology changes in response to predation pressure/presence.
tephra - CORRECT ANSWER - obvious band found in sediments produced by volcanic
ash
Riparian habitat - CORRECT ANSWER - habitat forming the boundary between
terrestrial and aquatic ecosystems
redox potential - CORRECT ANSWER - environmental conditions that control the
tendency for oxidizing or reducing chemical reactions to proceed (controlled mostly by oxygen [
])
True or False
1. most of the worlds available freshwater is found in large rivers
2. floods often increase the productivity of river food webs
3. stream order is used to describe a hierarchy of water clarity in streams
4. winterkill threatens only warm-water fishes in lakes that freeze
,5.acid rain was once a risk to all lakes in north America but conditions have improved recently
6. the paradox of the plankton questions why so many zooplankton species can coexist w high
densities of planktivorous fish
7. rotifers swim under the influence of very low Reynolds numbers
8. the N:P ratio of nutrients available to phytoplankton can regulate the types of phytoplankton
found in lakes
9.eutrophication of lakes and rivers can result from industrial-scale agriculture
10. rotifers are the only major zooplankton group that produces fossils that can be used in
paleolimnological studies
11. most of the CO2 that is release - CORRECT ANSWER - 1. false
2. true
3. false
4. false
5.false (not to all lakes)
6. false
7. true
8.true
9. true
10.false
11. false
12. false
13. true
How has climate warming during the last 50 years changed seasonal water flows in streams of
the PNW - CORRECT ANSWER - - lower snow pack (interferes with fresh water supply)
- reducing summer flows
- earlier spring flow (changes in precipitation density)
- earlier center-of-mass of seasonal stream flow timing (causes a surge of flooding at less
predictable times of year)
-warming lakes
, - shrinking glaciers
-trend towards warmer air temps
5 different variables that can be used in paleolimnological studies of lakes, and what they are an
indicator of - CORRECT ANSWER - 1. diatom: pH
2. sponge spicules: lake silica concentration
3. algal pigments: phytoplankton
4. N isotopes: Salon density
5. pollen: plants in wateshed
describe how the type of macrophytes found in littoral habitats changes along the depth gradient
in lakes - CORRECT ANSWER - - emergents found in shallow water, then floating, then
submergents in deepest water.
- gradient explained by the energy/resources allocated to stems vs leaves. In deep water,
producing really long stems is too expensive
Briefly describe how spawning populations of Pacific salmon affect biological, physical and
chemical processes in aquatic and riparian habitats in the Pacific Northwest and Alaska. Why
might these "salmon effects" be greater than the effects of the resident fishes in lakes and
streams? - CORRECT ANSWER - - the effects of salmon are greater than for resident
fishes b/c they come back w alot of energy and nutrients from the ocean
- biologically salmon are a source of food for lots of consumers
- chemically they are a source of nutrients (N and P)
- physically they are a source of disturbance that dislodges sediments or causes ecosystem
engineering.
Briefly describe why the processes of biomagnification and bioaccumulation lead to high PCB
concentrations in birds that prey on fishes - CORRECT ANSWER - - bioaccumulation is
the process where an organism can consume more contaminants than it can excrete , therefore its
concentrations are higher than water
- in biomagnification, you get successive jumps in contaminant concentration as you move up
through trophic position in a food chain
