Final Exam Biology 250 Version E2
Name ___________________________
Multiple choice, 3 points each
1. Which of the following statements about ecology is true?
a. Ecology involves the scientific study of interactions between organisms and their environment.
b. Ecology involves the scientific study of interactions that determine the distribution and abundance of
organisms.
c. Ecology is an interdisciplinary field that incorporates concepts from the natural sciences, politics, and
ethics.
d. Both a and b
e. Both b and c
2. The fundamental niche is _______ than the realized niche because the realized niche accounts for
_________.
a. smaller, interspecific interactions
b. larger, interspecific interactions
c. smaller, the fact that resources are limited
d. larger, the fact that resources are limited
e. sometime larger & sometimes smaller, interspecific interactions
3. Species richness is (on average) greatest at __________ latitudes and _________ elevation.
a. equatorial, lower
b. equatorial, middle
c. equatorial, higher
d. temperate, lower
e. temperate, middle
f. temperate, higher
g. polar, lower
h. polar, middle
i. polar, higher
NEXT TWO QUESTIONS:
The logistic growth model is: N0*e(rt)).When you use it to describe different populations (different
species, or the same species in different environments), you’d need to different values for some of the
variables to be accurate.
4. Which of the following will NOT vary by population?
a. N
b. e
c. r
5. Match each population or environment (in the left column) with the best answer in the right
column. Use each answer only once.
____ An environment with limited resources
____ Population size at carrying capacity
____ A population that would be strongly affected by genetic drift
____ A population of a k-selected species
a. N=K
b. N is small
c. K is small
d. r is small
6. Which of the following makes up a lower % of animal biomass than it does plant biomass?
a. Nitrogen
b. Carbon
c. Oxygen
d. Phosphorous
6. How do plants access the carbon that’s eventually used to create biomass?
a. Take it up from soil after it’s weathered from rocks
b. From CO2 in the atmosphere
c. Take it up from soil after it is fixed and made available by bacteria
d. Through a symbiotic relationship with mycorrhizae
7. Which of the following is the least attractive “food” source for microbes when they are
decomposing plant material?
a. Glucose
b. Fructose
c. Cellulose
d. Lignin
8. As glaciers melt and reveal rocks and dirt, albedo _________.
a. decreases
b. it’s a constant, so it neither decreases nor increases
c. increases
d. could increase or decrease depending on the abundance of bacteria in the revealed soil
9. Which of the following is not a way organisms can deal with a changing climate?
a. Phenotypic plasticity
b. Migration/range shifts
c. Evolution/adaptation
d. all of the above are correct
10. When nutrients are mineralized, they are converted from ____________________ by
___________.
a. organic to inorganic forms, microbes
b. organic to inorganic forms, plants
c. inorganic to organic forms, microbes
d. inorganic to organic forms, plants
d. organic to inorganic forms, microbes and plants
11. Which of the following would increase beta diversity. Choose more than one answer if needed.
a. a increase in average alpha diversity
b. a increase in gamma diversity
c. a species goes extinct in one population (out of many populations in the region)
d. a species goes extinct in all populations within the region
12. Soils are most “developed” (clearly defined layers, organic material reaches greater depths) in the
___________ stage of succession.
a. early, because plants haven’t taken up the organic matter
b. middle, because species richness is the highest so many different species influence the soil
c. late, because tree roots go deeper and plants are depositing more nutrients into the soil
d. it’s actually most developed before succession even starts but disturbances ruin soil development, so
none of the above make sense
e. it varies by environment and biome, so none of the above are true in all places
13. Which of the following would convert primary productivity into secondary productivity most
efficiently?
a. ant
b. snake
c. lion
d. pitcher plant (a carnivorous plant)
14. In the Costa Rica conservation reserves example from class, which of the following would NOT be
recommended by ideal reserve design?
a. The long, narrow northern corridor connecting reserves on the east and west coast
b. the large, circular Santa Rose marine reserve
c. the eight small reserves near Tambor
d. leaving a buffer between reserve space and the capital city, San Jose
15. Which of the following is true about N-fixing bacteria?
a. they’re always associated with (connected to) plant roots
b. they have no drawbacks from the plant’s perspective
c. they can exist in special modules on plant roots
d. all of the above are true
Short answer questions. Clearly define and explain the ecological importance of each concept, within
the space limits allowed. Draw figures or use examples to help illustrate your point if you’d like. (4
points each)
State Elton’s Biotic Resistance Hypothesis
Is atmospheric CO2 higher in summer or winter? Why?
Define genetic drift and give an example of when it may have a large impact
Grasses and grasshoppers have different nutritional requirements (C:N ratio). How are they different
and how does it affect the transfer of energy across trophic levels?
Compare and contrast GPP and NPP
Define interference competition, and give an example of how this might occur in nature
Longer answer. Choose 5 of 6, 6 points each.
Apis mellifera is an introduced pollinator. All pollinator visits (y-axis) not labeled as Apis mellifera are
provided by native pollinators. What recommendation would you make to a farmer that wanted to
ensure native pollinators visited her crops, and how would you use this graph to support that
recommendation? You’ll need to remember (from class) what the x-axis (distance class) means.
The x-axis should be labelled with different biomes. Place each of the following biomes where you’d
expect to see them along the x-axis (you don’t have to pick an exact bar, just choose left side or right
side): tropical forest, desert, boreal forest, tundra. Then, explain why we see so much variation in
percentage of NPP allocated to roots across different biome types.
Label the x-axes of the two figures below. One will be precipitation, one will be temperature. Explain
why the graph on the left side of the page is hump-shaped instead of constantly increasing.
(part of carbon cycle)
Carbon fixation by plants
How could the “ecology of fear” affect ecosystem processes? Define the “ecology of fear” and
ecosystem processes in your answer. Use the graph below in your answer, if you’d like.
If “s” stands for species, and “c” stands for clipping (meant
to simulate herbivory): Does species identity affect just
Microbial C, just Microbial N, both, or neither?
Does clipping affect just Microbial C, just Microbial N, both,
or neither?
Does the interaction of species identity and clipping affect
just Microbial C, just microbial N, both, or neither? Explain
in your own words what a statistically significant
interaction between species identity and clipping means,
using the graph if you’d like.
You want to test whether a loblolly pine forest is limited in its productivity by nitrogen,
phosphorus, or both. Design an experiment to test this. Sketch a graph of what the result would
look like if nitrogen were the limiting nutrient.