Uvic Bio 215 Final Exam
Define trophic levels. - *answers * The sequence of steps in a food chain or pyramid
What are the simplified steps for trophic levels? - *answers * Secondary consumer
Tertiary consumer
Primary consumer
Primary producer
How many trophic levels there is? - *answers * 4
Example of a trophic chain - *answers * tree→carerpillar→warbler→hawk
Describe food web complexity? - *answers * 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
Mean chain length - *answers * mean # of links running from primary producer to each of the
top predators
Connectance formula(C) - *answers * C=A/P where A is the number of actual links in a food
web.And P is the number of possible links in a food web.
How to find out possible links,If we have species - *answers * N=n(n-1)/2 where n is the
number of species
,Uvic Bio 215 Final Exam
Linkage Density(LD) - *answers * total number of links divided by total number of
species=average number of links per species
What is a dominant species? - *answers * A common species with an effect on the comment
proportional to its biomass.
What is an umbrella species also known as?
Describe.
Example. - *answers * Indicator species.
Used for conservation decisions.
"If you protect the umbrella,you protect everything underneath"
Grizzly Bear
What is a keystone species? - *answers * A species with an effect on the community that is
disproportional to its biomass.
e.g. bears,sea otters,starfish
"no many otters--large effect"
How to found a keystone on a graph? - *answers * smallest biomass and highest impact
Example of sea otter - *answers * When no sea otters(no fat--endotherms--pack air into base
layers of fur),urchin population grew exponentially causing kelp beds to dissapeared.
Proportional biomass of species - *answers *
Liebig's Law of the Minimum - *answers * Population numbers can be regulated by a single
resource that has the gratest relative scarcity
,Uvic Bio 215 Final Exam
A messenger molecule, also known as __________________, does what?
Example. - *answers * a keystone molecule
a chemical that has a disproportionate effect on the environment relative to abundance.
Dimethyl sulfide
Messenger molecule - *answers *
Nutrient cycling - *answers *
Downloading leads to - *answers * increased primary production in estuaries and adjecent
marine waters.develop gyres
Uploading - *answers * fertilizer from deposit bird poop from seabird colnies.
_______ are a dominant species. ________ are a keystone species. - *answers * Salmon
Bears
What is the relationship between salmon and oligotrophic lakes? - *answers * Migration of
salmon greatly increase primary productivity of these oligotrophic lakes and streams.
Increase in productivity proportional to abundance of salmon carcasses
Nutrient cycling can happen between marine and terrestrial ecosystems by what means?
Explain. - *answers * 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.
, Uvic Bio 215 Final Exam
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. - *answers * 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.
Reproduction condition of salmon captured by bears - *answers * Most of the predation is on
post-reproductive salmon
Bear predation has minor effect on the reproduction of salmon
Cleared and deep mountain lakes - *answers * clear because nothing in them.
Poor producers(oligothrophic-low productivity).
Nitrogen and phosphorous limited
Low planktown abundance
Usually few fish.
Salmon important for this lakes productivity
What is a riparian zone? - *answers * any forest habitat of a forest adjacent to a stream that is
affected by the stream. (Hydrology - cycle of water, nutrients).
Vegetation is directly influence by the body of water.
Relationship between bears and night - *answers * more successful at night because salmon
cannot see them,bears are lazy
Define trophic levels. - *answers * The sequence of steps in a food chain or pyramid
What are the simplified steps for trophic levels? - *answers * Secondary consumer
Tertiary consumer
Primary consumer
Primary producer
How many trophic levels there is? - *answers * 4
Example of a trophic chain - *answers * tree→carerpillar→warbler→hawk
Describe food web complexity? - *answers * 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
Mean chain length - *answers * mean # of links running from primary producer to each of the
top predators
Connectance formula(C) - *answers * C=A/P where A is the number of actual links in a food
web.And P is the number of possible links in a food web.
How to find out possible links,If we have species - *answers * N=n(n-1)/2 where n is the
number of species
,Uvic Bio 215 Final Exam
Linkage Density(LD) - *answers * total number of links divided by total number of
species=average number of links per species
What is a dominant species? - *answers * A common species with an effect on the comment
proportional to its biomass.
What is an umbrella species also known as?
Describe.
Example. - *answers * Indicator species.
Used for conservation decisions.
"If you protect the umbrella,you protect everything underneath"
Grizzly Bear
What is a keystone species? - *answers * A species with an effect on the community that is
disproportional to its biomass.
e.g. bears,sea otters,starfish
"no many otters--large effect"
How to found a keystone on a graph? - *answers * smallest biomass and highest impact
Example of sea otter - *answers * When no sea otters(no fat--endotherms--pack air into base
layers of fur),urchin population grew exponentially causing kelp beds to dissapeared.
Proportional biomass of species - *answers *
Liebig's Law of the Minimum - *answers * Population numbers can be regulated by a single
resource that has the gratest relative scarcity
,Uvic Bio 215 Final Exam
A messenger molecule, also known as __________________, does what?
Example. - *answers * a keystone molecule
a chemical that has a disproportionate effect on the environment relative to abundance.
Dimethyl sulfide
Messenger molecule - *answers *
Nutrient cycling - *answers *
Downloading leads to - *answers * increased primary production in estuaries and adjecent
marine waters.develop gyres
Uploading - *answers * fertilizer from deposit bird poop from seabird colnies.
_______ are a dominant species. ________ are a keystone species. - *answers * Salmon
Bears
What is the relationship between salmon and oligotrophic lakes? - *answers * Migration of
salmon greatly increase primary productivity of these oligotrophic lakes and streams.
Increase in productivity proportional to abundance of salmon carcasses
Nutrient cycling can happen between marine and terrestrial ecosystems by what means?
Explain. - *answers * 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.
, Uvic Bio 215 Final Exam
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. - *answers * 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.
Reproduction condition of salmon captured by bears - *answers * Most of the predation is on
post-reproductive salmon
Bear predation has minor effect on the reproduction of salmon
Cleared and deep mountain lakes - *answers * clear because nothing in them.
Poor producers(oligothrophic-low productivity).
Nitrogen and phosphorous limited
Low planktown abundance
Usually few fish.
Salmon important for this lakes productivity
What is a riparian zone? - *answers * any forest habitat of a forest adjacent to a stream that is
affected by the stream. (Hydrology - cycle of water, nutrients).
Vegetation is directly influence by the body of water.
Relationship between bears and night - *answers * more successful at night because salmon
cannot see them,bears are lazy
