Bio 220w Exams 2 And 3

83 Questions | Total Attempts: 59

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Bio 220w Exams 2 And 3 - Quiz

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Questions and Answers
  • 1. 
    Two populations of white-tailed deer have the same density but different abundances of deer. This is possible because: 
    • A. 

      One population has well-defined boundaries whereas the other does not.

    • B. 

      One population has a greater number of available resources than the other.

    • C. 

      One population has a greater number of available resources than the other

    • D. 

      One population has more individuals and occupies a larger area than the other.

    • E. 

      This is not possible, as density and abundance measure the same thing.

  • 2. 
    What is a limitation of the number of trophic levels that can be supported in an ecosystem?
    • A. 

      The increase in biomass from one trophic level to the next.

    • B. 

      The rate of energy cycling in an ecosystem

    • C. 

      The gain of energy as it flows through each trophic level in an ecosystem

    • D. 

      The loss of energy as it flows through each trophic level in an ecosystem

    • E. 

      The loss of energy during photosynthesis by producers

  • 3. 
    The red poison arrow frog is highly toxic to its predators. What protective mechanism is the exploited population most likely using to avoid being driven to extinction by exploiters?
    • A. 

      Predator satiation

    • B. 

      Spatial refuge

    • C. 

      Large body size

    • D. 

      Crypsis

    • E. 

      Chemical defense

  • 4. 
    The figure below shows the age structure of sardines from fished areas (black bars) and protected unfished areas (grey bars) in 2003. From this, we can determine that
    • A. 

      Fishing has had no impact on the population age distribution of sardines

    • B. 

      Fishing has increased the number of older individuals in the population

    • C. 

      Sardine populations in protected areas have a more even age distribution.

    • D. 

      Banning fishing of sardines would not achieve anything as there are no recruits that could replace the adults in the fished popula

    • E. 

      because sardines don’t breed until 1 year of age, we would not expect to find any juveniles within the fished areas in 2004.

  • 5. 
    Which would be best modeled by the geometric growth equation? if(window["setInfo"]){setInfo("3101a33e-b562-4091-84e3-488136436599:choiceInteraction:RESPONSE", 1)}
    • A. 

      Weedy plants that complete their entire life cycle in one year

    • B. 

      Coral reef fish that compete for territories

    • C. 

      Grass that is eaten by deer.

    • D. 

      Birds with continuous reproduction.

    • E. 

      Foxes that are infected by mange mites.

  • 6. 
    How do keystone species differ from dominant species?
    • A. 

      Keystone species have a large effect on a community, but dominant species do not.

    • B. 

      The keystone species in a community have greater total biomass than dominant species have

    • C. 

      Dominant species have greater total biomass than keystone species.

    • D. 

      Dominant species have a large effect on a community, but keystone species do not.

    • E. 

      Keystone species do not differ from dominant species.

  • 7. 
    Which of these is an example of top-down control of an ecosystem? if(window["setInfo"]){setInfo("598f65c2-2b9f-4a2b-a38f-c9fb4f2f3edb:choiceInteraction:RESPONSE", 1)}
    • A. 

      Drought reduces the rate of primary production by grasses in a prairie.

    • B. 

      Fire decreases species richness in a forest.

    • C. 

      The reintroduction of wolves decreases herbivory by deer, which increases the population of primary producers

    • D. 

      The invasion of the emerald ash borer is followed by the invasion of its parasitoids.

    • E. 

      Runoff of fertilizer from a farm into a lake causes the population of lake algae to grow at exponential rates.

  • 8. 
    In this 2-species isocline diagram for the Lotka-Volterra competition model, which of the following statements is correct?
    • A. 

      There is stable coexistence of both species

    • B. 

      Species 1 always wins.

    • C. 

      Species 2 always wins.

    • D. 

      Species 1 or Species 2 may win.

    • E. 

      Both species go extinct

  • 9. 
    If a population is growing, Nt+1 would be the result of: if(window["setInfo"]){setInfo("2b8bf105-1130-4737-9edc-b9e29e052619:choiceInteraction:RESPONSE", 1)}
    • A. 

      High rates of emigration and low rates of immigration, and the value of Nt

    • B. 

      High rates of immigration and low rates of emigration, and the value of Nt

    • C. 

      high rates of immigration and low rates of emigration

    • D. 

      Stable populations dynamics, and the value of Nt.

    • E. 

      High birth rates and low death rates.

  • 10. 
    When do mutualistic interactions evolve?
    • A. 

      When one species benefits and the other species is harmed by the interaction

    • B. 

      When the cost is greater than the benefit for both species

    • C. 

      When the benefit is greater than the cost of the interaction for both species

    • D. 

      When resources are unlimited

    • E. 

      When competing species have coexisted over a long period of time

  • 11. 
    A population’s value of lambda (λ) can provide insight into:
    • A. 

      How quickly it is growing.

    • B. 

      how long between each successive generation.

    • C. 

      How long individuals of this species live.

    • D. 

      its logistic rate of increase

    • E. 

      Its net reproductive rate

  • 12. 
    At Penn State, the carrying capacity of squirrels is 1,000 squirrels. The maximum rate of increase of this squirrel population is 2 squirrels per year. This year there are 200 squirrels. What is the current rate of squirrel population change?
    • A. 

      1600 per year

    • B. 

      800 per yea

    • C. 

      400 per year

    • D. 

      320 per year

    • E. 

      2 per year

  • 13. 
    A food web is a(n):
    • A. 

      List of all the species in a community.

    • B. 

      Alternative way to calculate species evenness.

    • C. 

      Diagram of the mutualistic interactions in a community

    • D. 

      Summary of the feeding relationships in a community.

    • E. 

      Map of energy flow into and out of an ecosystem.

  • 14. 
    In order to determine whether important life history traits are age-dependent, we can:
    • A. 

      Conduct longitudinal studies of cohorts

    • B. 

      Conduct latitudinal studies of cohorts

    • C. 

      Construct BIDE parameter space pyramids of individuals

    • D. 

      Examine the age structure of populations

    • E. 

      Not waste out time testing this as life history traits vary among individuals in a population, not with age.

  • 15. 
    In this marine interaction web, if the interaction between algae (1) and sponges (3) is a mutualism, and the jellyfish (5) is a predator of sponges (3), what is the jellyfish's (5) effect on algae (1)?  if(window["wireUpEvent"]){Assessment.wireUpEvent("5d98fbce-3994-4317-83d6-202db0ae174c:choiceInteraction:RESPONSE:answerChoice5")}  
    • A. 

      This is a direct interaction; jellyfish (5) has a negative effect on algae (1).

    • B. 

      This is an indirect interaction; jellyfish (5) has a negative effect on algae (1).

    • C. 

      This is a direct interaction; jellyfish (5) has a positive effect on algae (1).

    • D. 

      This is an indirect interaction; jellyfish (5) has a positive effect on algae (1).

    • E. 

      It is not possible for jellyfish (5) to have any effect on algae (1).

  • 16. 
    You are studying a small island in the Gulf of Mexico, and comparing the species diversity before and after last year's oil spill. Before the spill, you find three species of marsh grass, which are all equally abundant. After the oil spill, there are still the same three species, but the relative abundance of each has changed so that 50% of the community is one species, and the other two species are 25% and 25%. Which of the following describes the change in diversity?
    • A. 

      The rank abundance curve will get longer

    • B. 

      The rank abundance curve will get shorter.

    • C. 

      The Shannon-Wiener index will increase

    • D. 

      The Shannon-Wiener index will decrease

    • E. 

      The species richness will increase.

  • 17. 
    You have been conducting a long-term study on an insect that only lives for a single year. You need to know how many insects you would expect to find in that population when you come back next year. How would you calculate this using a life history table you have constructed for the population this year?
    • A. 

      By determining whether the values of R0 and r are the same for this population

    • B. 

      By calculating λ

    • C. 

      By multiplying the number of animals in the population this year by the population’s generation time (T).

    • D. 

      By multiplying the number of animals in the population this year by the population's R0 value.

    • E. 

      ) The lxmx values would give you the population size for each year.

  • 18. 
    You are studying a new invasive species in Pennsylvania, the rusty crayfish. Under which of the following conditions is the rusty crayfish population most likely to exhibit unlimited growth?
    • A. 

      When the population is at its carrying capacity

    • B. 

      When resources are abundant

    • C. 

      When intraspecific competition is stronger than interspecific competition

    • D. 

      When there is no conflict between its mutualists.

    • E. 

      Unlimited growth is not possible in a natural population.

  • 19. 
    Which of the following is NOT part of the keystone predator hypothesis?
    • A. 

      Predators keep prey populations below their carrying capacity

    • B. 

      Predators prevent competitive exclusion between prey populations

    • C. 

      Predators increase the number of species that can coexist in a community

    • D. 

      Removing a top predator is predicted to decrease community species richness.

    • E. 

      The effect of predators on the community depends upon species evenness in the community

  • 20. 
    The Puccinia rust fungus infects the plant Arabis, causing Arabis to produce pseudoflowers which are structures that look like flowers, but are actually covered in spores of the fungus. Bees visit these pseudoflowers, and then spread the spores to other plants. The Puccinia-Arabis exploitative interaction is taking advantage of a:
    • A. 

      Reproduction mutualism

    • B. 

      Mycorrhizae mutualism

    • C. 

      Nitrogen fixing mutualism

    • D. 

      Protective mutualism

    • E. 

      Digestive mutualism.

  • 21. 
    We can interpret the competitive exclusion principle to mean that
    • A. 

      two species can act in cooperation to exclude a third species

    • B. 

      Competition can be so intense that both species eventually die

    • C. 

      Two species with identical niches cannot coexist indefinitely

    • D. 

      Two species with identical niches can hybridize and form a new species

    • E. 

      Two species with identical niches do not compete

  • 22. 
    In geometric growth, the size of each generation differs from the next by
    • A. 

      the birth rate.

    • B. 

      A variable growth rate

    • C. 

      The death rate.

    • D. 

      a constant growth rate.

    • E. 

      The immigration rate.

  • 23. 
    You are trying to determine if grasshoppers compete with caterpillars for corn, which is their shared food source. For their interaction to be interspecific competition,
    • A. 

      Grasshoppers use caterpillars as food

    • B. 

      Grasshoppers protect the caterpillars in exchange for food.

    • C. 

      Both species eat more corn when they are together compared to when each species is alone

    • D. 

      Caterpillars eat more corn and grasshoppers eat less corn when the two species are together, compared to when each species is alone.

    • E. 

      Both caterpillars and grasshoppers eat less corn when the two species are together compared to when each species is alone.

  • 24. 
    In the Lotka-Volterra predator-prey model:
    • A. 

      carrying capacity determines the population size of the predator

    • B. 

      competition for resources limits the population size of the prey.

    • C. 

      Population growth of the prey is exponential when the predator is absent

    • D. 

      Predator mortality does not influence the predator population.

    • E. 

      Predation rate does not influence the prey population.

  • 25. 
    You are studying a native bee, and trying to decide if it is a keystone mutualist. For this mutualist species to be a keystone,
    • A. 

      Its removal should result in a loss of species richness

    • B. 

      Its removal should result in a gain of species richness.

    • C. 

      Its removal should result in no change of species richness

    • D. 

      Adding more individuals of the mutualist species will decrease species richness.

    • E. 

      replacing it with a non-keystone species should result in no change of species richness

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