Uvic Bio 215 Final Exam UPDATED Exam
Questions and CORRECT Answers
Define trophic levels. - CORRECT ANSWER - the sequence of steps in a food chain or
pyramid
What are the simplified steps for trophic levels? - CORRECT ANSWER - Secondary
consumer
Tertiary consumer
Primary consumer
Primary producer
Describe food web complexity? - CORRECT ANSWER - 1) number of trophic levels
2) chain length- number of links running from a primary producer to a top predator
3) connectance- actual number of links in a food web divided by the total number of possible
links
-if a community has n species, then total number of possible links is N= [n(n-1)] /2
4) linkage density - number of links per species
What is a dominant species? - CORRECT ANSWER - A common species with an effect
on the comment proportional to its biomass.
What is an umbrella species also known as?
Describe.
Example. - CORRECT ANSWER - Indicator species.
Used for conservation decisions
Grizzly Bear
,What is a keystone species? - CORRECT ANSWER - a species with an effect on the
community that is disproportional to its biomass.
A messenger molecule, also known as __________________, does what?
Example. - CORRECT ANSWER - a keystone molecule
a chemical that has a disproportionate effect on the environment relative to abundance.
Dimethyl sulfide
_______ are a dominant species. ________ are a keystone species. - CORRECT
ANSWER - Salmon
Bears
Nutrient cycling can happen between marine and terrestrial ecosystems by what means? Explain.
- CORRECT ANSWER - Downloading of nutrients from land to sea. Rivers discharge
sediment, trace elements, dissolved organic matter, nitrogen, phosphates into marine systems.
Increase primary production of estuaries and adjacent marine waters.
Uploading of nutrients from sea to land. Example, fish being spread across the world, fertilizers,
etc.
Explain the simplified salmon food web of the North Pacific. - CORRECT ANSWER -
Stream - estuary - ocean - river - etc.
Growth of ulva proportional to amount of nitrogen and phosphorous released by salmon
carcasses.
Copepods eat ulva.
Baby salmon eat copepods.
Feedback loop!
What is a riparian zone? - CORRECT ANSWER - any forest habitat of a forest adjacent to
a stream that is affected by the stream. (Hydrology - cycle of water, nutrients)
, Bears are a large contributor to the uploading of salmon carcasses from rivers (hence they are a
________ species.) Although, bears have little effect on salmon population because? -
CORRECT ANSWER - Keystone
They may take the reproductive adults, however most are post reproductive.
Nitrogen is a ________ resource because: - CORRECT ANSWER - Limiting
Most vegetation depends on this resource
_____ of Earth's atmosphere is nitrogen. - CORRECT ANSWER - 78%
What are the two stable isotopes of nitrogen? - CORRECT ANSWER - 14N - light
isotope, 99.3% of total nitrogen
15N - heavy isotope, 0.7% of total nitrogen, 7 parts per thousand (ppt)
In the Caste River example, the nitrogen-rich plants indicators were found where? Why? -
CORRECT ANSWER - Below the falls,
Because they are below the salmon barrier (i.e. more nutrients)
Up to _____ of the nitrogen in riparian plants is derived from salmon nutrients. - CORRECT
ANSWER - 80%
The Wren was found to be ____ higher in density ____ the falls because: - CORRECT
ANSWER - 50%
below
30-95% of insect diet was salmon derived
_____ of autumn protein consumption by bears is derived from salmon. - CORRECT
ANSWER - 95%
Questions and CORRECT Answers
Define trophic levels. - CORRECT ANSWER - the sequence of steps in a food chain or
pyramid
What are the simplified steps for trophic levels? - CORRECT ANSWER - Secondary
consumer
Tertiary consumer
Primary consumer
Primary producer
Describe food web complexity? - CORRECT ANSWER - 1) number of trophic levels
2) chain length- number of links running from a primary producer to a top predator
3) connectance- actual number of links in a food web divided by the total number of possible
links
-if a community has n species, then total number of possible links is N= [n(n-1)] /2
4) linkage density - number of links per species
What is a dominant species? - CORRECT ANSWER - A common species with an effect
on the comment proportional to its biomass.
What is an umbrella species also known as?
Describe.
Example. - CORRECT ANSWER - Indicator species.
Used for conservation decisions
Grizzly Bear
,What is a keystone species? - CORRECT ANSWER - a species with an effect on the
community that is disproportional to its biomass.
A messenger molecule, also known as __________________, does what?
Example. - CORRECT ANSWER - a keystone molecule
a chemical that has a disproportionate effect on the environment relative to abundance.
Dimethyl sulfide
_______ are a dominant species. ________ are a keystone species. - CORRECT
ANSWER - Salmon
Bears
Nutrient cycling can happen between marine and terrestrial ecosystems by what means? Explain.
- CORRECT ANSWER - Downloading of nutrients from land to sea. Rivers discharge
sediment, trace elements, dissolved organic matter, nitrogen, phosphates into marine systems.
Increase primary production of estuaries and adjacent marine waters.
Uploading of nutrients from sea to land. Example, fish being spread across the world, fertilizers,
etc.
Explain the simplified salmon food web of the North Pacific. - CORRECT ANSWER -
Stream - estuary - ocean - river - etc.
Growth of ulva proportional to amount of nitrogen and phosphorous released by salmon
carcasses.
Copepods eat ulva.
Baby salmon eat copepods.
Feedback loop!
What is a riparian zone? - CORRECT ANSWER - any forest habitat of a forest adjacent to
a stream that is affected by the stream. (Hydrology - cycle of water, nutrients)
, Bears are a large contributor to the uploading of salmon carcasses from rivers (hence they are a
________ species.) Although, bears have little effect on salmon population because? -
CORRECT ANSWER - Keystone
They may take the reproductive adults, however most are post reproductive.
Nitrogen is a ________ resource because: - CORRECT ANSWER - Limiting
Most vegetation depends on this resource
_____ of Earth's atmosphere is nitrogen. - CORRECT ANSWER - 78%
What are the two stable isotopes of nitrogen? - CORRECT ANSWER - 14N - light
isotope, 99.3% of total nitrogen
15N - heavy isotope, 0.7% of total nitrogen, 7 parts per thousand (ppt)
In the Caste River example, the nitrogen-rich plants indicators were found where? Why? -
CORRECT ANSWER - Below the falls,
Because they are below the salmon barrier (i.e. more nutrients)
Up to _____ of the nitrogen in riparian plants is derived from salmon nutrients. - CORRECT
ANSWER - 80%
The Wren was found to be ____ higher in density ____ the falls because: - CORRECT
ANSWER - 50%
below
30-95% of insect diet was salmon derived
_____ of autumn protein consumption by bears is derived from salmon. - CORRECT
ANSWER - 95%
