BIO360 Exam 3 Key
(Questions are identical in Code 16, but in a different order)

Multiple Choice Questions (2 pts each)

1. Larger populations of plants or animals will be found in habitat patches that are ______ in area and ________ isolated from other patches.
A. smaller, more
B. smaller, less
C. larger, more
D. larger, less

2. In a metapopulation model, new subpopulations are added through __________, and old subpopulations are lost through ___________.
A. colonization, extinction
B. extinction, colonization
C. birth, death
D. death, birth

3. A source population is defined as having:
A. population growth (λ) less than one
B. population growth (λ) more than one
C. A or B
D. None of the above

4. A term used to describe a species interaction that results in the population growth rate of one species increasing and the other species decreasing is:
A. competition
B. herbivory
C. mutualism
D. commensalism
E. amensalism

5. An example of a behavior that an infectious disease modifies in its human host to promote its transmition is:
A. sneezing
B. rubbing eyes
C. biting
D. induced excretion
E. all of the above

6. In the S-I-R model of disease transmission, what value of R0 will result in a disease epidemic when a small number of infectious individuals are introduced into the population?
A. R0 = 0
B. R0 > 1 
C. R0 = 1
D. R0 < 1 

7. What is unique about HIV that causes its rapid evolution?
A. It has a high rate of mutation
B. It experiences strong selection against certain varieties
C. It has high population size
D. It has high population growth rates
E. All of the above

8.  “Use of natural enemies (parasites, predators, and disease) to control pest population sizes” defines:
A. biocontrol
B. predation
C. coexistence
D. competition
E. displacement

9. With repeated introduction in Australia of a virus (myxamatosis) that infected European Rabbits, the mortality of rabbits per introduction ___________ over time.
A. increased
B. did not change
C. decreased

10. In comparison to mainland habitats where lynx are present, the population sizes of hares on islands where lynx were absent
A. showed nearly identical changes over time
B. rose higher and fell lower than those on the mainland
C. where more constant (less rise and fall) over time
D. were unrelated to the presence of lynx

11.  The mathematical models for predators and prey begin from which of the following models that we learned previously?
A. energy balance equation
B. exponential population growth equation
C. logistic population growth equation
D. life table equation

12.  In the Lotka-Volterra predator-prey model, which term refers to the capture efficiency of prey by predators?
A. a
B. b
C. c
D. d
E. r

13.  The relationship between the number of prey and the number of prey captured by predators is called:
A. exponential growth
B. the functional response
C. the coexistence capacity
D. interaction stability

14.  An example of exploitation competition is:
A. the reduction in soil nitrogen by two different plant species
B. the reduction in bacteria by two different paramecium species
C. the reduction in berries or fish by two different bear species
D. all of the above

15. The best competitor is the one that
A. grows biggest
B. (for animals) runs fastest
C. can survive at the lowest level of its resource
D. consumes the most food
E. none of the above

16. Scientists originally thought one plant was excluding nearby plants through competition. They later found this plant harbored mice that predated the other plant’s seeds.  This is an example of:
A. apparent competition
B. predatory competition
C. exploitative competition
D. character displacement

17. Character displacement:
A. occurs when competing species converge to use similar resources.
B. refers to the evolution of different species in isolation.
C. can be identified by comparing characteristics of populations (for example, bill depth of birds) of competing species living together or living separately.
D. only happens in plant populations.

18. The mathematical models for competition between species begin from which of the following models that we learned previously?
A. energy balance equation
B. exponential population growth equation
C. logistic population growth equation
D. life table equation

19.  In the competition equations developed by Lotka and others, what does the term αN2 represent?
A. instantaneous rate of population increase of species 1
B. carrying capacity of the environment for species 1
C. reduction of species 1's carrying capacity by individuals of species 1
D. reduction of species 1's carrying capacity by individuals of species 2

20. In two-species competition, what is true when stable coexistence is achieved under the Lotka-Volterra competition model?
A. Species 1 limits Species 2 more than it limits itself
B. Species 2 limits Species 1 more than it limits itself
C. Species 1 and Species 2 both limit each other more than they limit themselves
D. Species 1 and Species 2 both limit themselves more than they limit each other
E. None of the above

21.  A category of mutualism is:
A. dispersive
B. defensive
C. trophic
D. all of the above
E. none of the above

22. When yucca moths lay more than seven eggs in a yucca flower, the moths:
A. increase number of caterpillars that then become adults
B. increase their population growth rate
C. cause more yucca flowers to be aborted
D. decrease their pollination of flowers

23.  A harmless butterfly that has adopted the coloration of a toxic butterfly is an example of
A.  Batesian mimicry
B.  Reproductive mimicry
C.  Mullerian mimicry
D.  Behavioral mimicry

24. Acacia plants
A. provide a place for ants to live within their thorns
B. provide food (nectar and proteins) for ants
C. are defended by ants from herbivores
D. all of the above
E. none of the above

25. In its native range, cane toad populations are mostly regulated by predators, but that is not the case in Australia, because:
A. there are no predators in Australia
B. the toads are too big to fit in the mouths of potential predators
C. the toad populations are regulated by the availability and seasonality of cane beetle prey
D. the toads secrete toxins that can kill potential predators
E. toads live in human settlements where they are not exposed to predators

26. When examining the potential distribution of an invasive species (such as pythons), ecologists can utilize information from their native range to predict a future distribution map of the invasive species.  This approach typically uses what abiotic/biotic variables to make those predictions?
A. climatic data
B. distance to human settlement
C. distance to the nearest port of entrance
D. tree density
E. distance to agricultural lands

27.  Since the Cambrian Explosion nearly 600 million years ago, the diversity of plants and marine animals has:
A. decreased
B. remained fairly constant
C. increased only
D. mainly increased, with some decline during periods of mass extinction
E. increased in plants, but decreased in marine mammals

28.  Once continuous populations may split because of:
A. founder effects
B. vicariance events
C. continental drift
D. geologic change, such as in the location of mountain ranges
E.  All of the above

29. Species arise when a small number of individuals become isolated at the periphery of their range. This defines:
A. convergence
B. allopatry
C. sympatry

30. Competition of individual grizzly bear with each other is termed _________ , and differs from their competition with black bear, termed ____________.
A. intraspecific, interspecific
B. apparent, interspecific
C. symmetric, asymmetric
D. interspecific, intraspecific

Short Answer or Short Essay Questions

31a.  (4 pts) In Dr. Haddad’s study, name three different groups of species whose dispersal was increased by corridors:
1. butterflies
2. small mammals
3. plants
-- pollen

31b.  (3 pts) How did corridors influence the number of plant species?
Corridors increased the number of plant species

32a.  (3 pts)  What are on the three corners of the “disease triangle”?
host, pathogen, environment

32b.  (3 pts)  Define “infectious disease”
Infectious disease is a condition that is harmful to the host, caused by a parasite or pathogen

33.  Consider the graphic below, representing the competition between two species of oaks, red oaks and white oaks:

33a.  What does the α next to the y-axis refer to? (2 pts)
This converts the effect of white oaks on population of red oaks into terms of red oaks

33b.  What does the dashed line represent? (2 pts)
dN1/dt = 0

33c.  If the population sizes of the oaks start at values represented by the ‘X’, what will happen to the population sizes of each oak species over time? (2 pts)
They both increase

33d.  If the population sizes of the oaks start at values represented by the dot (where the lines cross), what will happen to the sizes of their populations over time? (2 pts)
They are at equilibrium (no change)

34.  (5 pts) How do biological factors in the evolution of interacting species differ those of physical environmental factors?
Biological factors stimulate mutual evolutionary responses in traits of interacting populations. Physical factors do not.  Biological factors promote a diversity of adaptations.

35a.  (2 pts) With what group of organisms did Gause and Luckinbill conduct predator-prey experiments in the lab?

35b. (3 pts)  In these experiments, what two environmental characteristics allowed the predator and prey to coexist for a longer duration?
1. lower food for prey
2. more spatial variation (larger area)

36.  (3 pts)  What is “asymmetric competition”, that, for example, allows two different barnacles (Balanus and Chthalmus) to coexist in the intertidal zone?
Asymmetric competition occurs when one species has allocated more to competition, able to out-compete the other species. The other species allocates more to stress tolerance.

37a. In the Invasion Curve below, label the x and y axes (3 pts),
x-axis: time
y-axis: Population Size
37b. (3 pts) Explain when would be the best time to be proactive and try to prevent further invasions via full eradication efforts, versus when management becomes reactive and is largely focused on controlling local populations when necessary for conservation of other species or communities.
To prevent further invasion, the best time to manage is at the initial introduction, when population size and range are small.  When population sizes are high, people can only react in some areas to limited effect.