Deck 7: Predation, Grazing and Disease

Question 1

If a plant were grazed upon by individuals of a snail population,and the plant produced compounds to deter further feeding,then what might occur?

A) The plant will do nothing different since it is now chemically defended.
B) The plant may experiences a trade-off of some sort, because there is likely a cost to producing the compounds that deter grazers.
C) The plant will not experience any trade-offs since it has evolved with this grazing snail.
D) The snail will likely continue to graze because it is immune to the chemicals this plant produces.

Answer 1

B

Question 2

You plan an experiment to clip a third of a plant's biomass to test how a plant species responds to herbivory.This plant is normally grazed on between April to June.You plan to run the experiment through September using a greenhouse.Given your understanding of plant compensation,which prediction regarding fruit production may occur during your experiment?

A) The plant will compensate none the less, and produce just as much fruit because its fitness will otherwise be affected.
B) The plant will die because it will not be able to grow back the clipped biomass.
C) The plant will not compensate and fruit production will decrease because it would likely only compensate during the time of year it is used to experiencing herbivory
D) The plant will produce new shoots to compensate for the clipping

Answer 2

C

Question 3

The type of predator can negatively impact prey populations if the predator?

A) Selectively removes breeding individuals
B) Selectively removes sick individuals
C) Selectively removes equal numbers of males and females
D) Selectively alternates between prey types

Answer 3

A

Question 4

In Figure 7.2a,which of the following statements is an accurate assessment of what happened with nestlings by the time the experiment ended?

A) Individuals in both treatments reached similar sizes and the number of fledglings was the same regardless of parasitism
B) Individuals from both treatments had about the same mass regardless of parasitism
C) Nestlings in unlined nests had more variation in their mass than did nestlings in lined nests
D) Body mass of nestlings between treatments was not significantly different.

Question 5

In Figure 7.4b,under which condition does Cuscuta salina significantly affect competitive interactions?

A) In 1994 when Salicornia is infected with C. salina
B) In 1995 when Arthrocnemum is infected with C. salina
C) In 1995 when Salicornia is infected with C. salina
D) In 1995 when Arthrocnemum is infected with C. salina

Question 6

Which type of organism typically does not kill their prey,but consumes part of each prey item,and does not need a host?

A) True predator
B) Grazer
C) Parasite
D) Parasitoid

Question 7

Explain why in Figure 7.11,vole abundances in experimental enclosures would drop to the same abundance as the control.

A) This is likely due to voles being preyed upon in the exclosures by predators.
B) Competition for food resources likely led to the vole population decline.
C) There is no change in vole populations through time.
D) The vole population in the exclosures likely included cannibals that reduced the population to that of controls.

Question 8

Which term defines an organism that reduces the growth,fecundity,or survival of another living organism that it consumes?

A) Prey
B) Saprotroph
C) Predator
D) Producer

Question 9

Compensation in plants due to herbivory might occur differently depending on which of the following factors?

A) Whether it is grazed on during a time of year when herbivores typically graze.
B) There should be no difference ever.
C) If the plant is a CAM plant or C4 plant.
D) Marine plants always produce more defensive compounds when grazed then terrestrial plants.

Question 10

In Figure 7.10a,which age group experiences the greatest risk of death by cheetah predation?

A) Adults
B) Subadults
C) Fawns
D) Adolescents

Question 11

A spider that spins a web to capture prey would be considered which of the following?

A) A foraging predator
B) A sit-and-wait predator
C) A grazer
D) A parasitoid

Question 12

When predators consume prey there is not always a negative effect on prey populations because?

A) Prey hide more when predators are nearby
B) Predation can reduce intraspecific competition
C) Predators tend to select the healthiest prey
D) Predators tend to select breeding individuals as their prey

Question 13

You have been studying a plant species for the last three years.On an island trip you notice that the same species there does not have a similar leaf morphology compared to that on the mainland.Specifically,the island plants do not have sharp points around the perimeter of each leaf and are instead very smooth.You also learn that this island is devoid of deer,which specialize on this plant.What might you hypothesize regarding the morphological differences between these plants?

A) Leaves have evolved differently on the island because of climate.
B) Leaves have no need on the island for morphological defenses because their primary predator is not found there.
C) There is no way the two plants are the same species.
D) Specialized predators on the island ate the spikes off of these leaves.

Question 14

What type of organism relies on a host,but it does not usually kill it?

A) Parasitoid
B) Parasite
C) Predator
D) Prey

Question 15

Which type of organism attacks their prey,kills it,and then consumes it?

A) Parasitoid
B) True Predator
C) Parasite
D) Grazer

Question 16

In Figure 7.1,the effects of mollusk grazing are shown for a number of plant traits in natural and experimental populations.As measured by relative difference,how much greater was seed production in the natural population compared to the experimental population?

A) It was not greater
B) It was approximately equal
C) It was 1.5 units greater
D) It was greater than 0.475 units

Question 17

You are working on a research project to study insects in a tropical rainforest.You have collected some larvae from a species of interest and brought them back to lab.Within a few days of rearing them,you notice that many have been consumed from the inside out and are dead.Upon closer inspection you find that there is another species of insect larvae present.Speculate how this could have happened.

A) The larvae cannibalized one another
B) The larvae were attacked by a predatory insect
C) It appears that you misidentified some of the larvae
D) The larvae were apparently host of a parasitoid fly or wasp

Question 18

In Figure 7.4c,which plants mass was greatest prior to being infected with Cuscuta salina?

A) Salicornia
B) Limonium
C) Frankenia
D) Dodder

Question 19

In Figure 7.7a,simulated herbivory caused Ascophyllum nodosum to produce amounts of phlorotannins similar to which of the following?

A) The control treatment
B) The grazed treatment
C) The control and grazed treatment
D) Amounts of phlorotannins significantly differed between simulated herbivory treatments and the control

Question 20

What is one reason that predators may no have a significant impact on prey populations as a whole?

A) Predator populations are usually less abundant than prey populations
B) Prey populations are usually less abundant than predator populations
C) Predators typically feed on individuals that currently make little to no reproductive contribution to the prey population
D) Predators typically feed on reproductively active females

Question 21

A metapopulation:

A) Refers to the patchiness that can occur in populations
B) Can be useful in understanding why population fluctuations are often dampened
C) Usually refers to two subpopulations
D) Has individuals that usually do not disperse between subpopulations

Question 22

Select which of the following choices are correct.

A) Predator populations can be impacted by other predators
B) When predator numbers increase there is often a density dependent negative impact on the predator species
C) The lynx and hare population cycles are easily explained by Lotka Volterra models
D) Parasites rarely interfere with one another

Question 23

Mistletoe is a plant that grows on other plants and is best categorized as a

A) Symbiont
B) Predator
C) Parasitoid
D) Parasite

Question 24

Plants can produce chemical defenses against herbivores:

A) In response to herbivory
B) To deter many different species of herbivores
C) Often at an energetic cost
D) Not necessarily in response to mechanical damage

Question 25

If prey are experimentally protected from predators then:

A) Prey numbers typically decrease quickly
B) Prey numbers may increase but then decrease when resources become limiting
C) Prey numbers usually do not change
D) Prey numbers are not dependent on predators

Question 26

If a plant produces chemical defenses in response to grazers this could be called

A) A communication response
B) An induced response
C) An energy deficiency response
D) An anticipated response

Question 27

One must keep in mind when using ecological mathematical models:

A) Ecological interactions in nature are typically more complex than the model provides for
B) That models typically incorporate most relevant ecological factors
C) That models typically do not have assumptions built into them
D) None of the above

Question 28

Which of the following might be considered an optimal foraging situation?

A) How students arrange themselves in a classroom.
B) How real estate developers design and distribute strip malls.
C) Where advertisers place ads on web pages.
D) None of the above.

Question 29

Predation can be thought of as:

A) An extreme form of parasitism
B) A community disturbance
C) A process that occurs in the absence of competition
D) A process that can promote species coexistence

Question 30

It appears that more species of mussels can coexist when sea stars are present then when they are not.This would be an example of:

A) The competitive exclusion principle.
B) N-dimensional hypervolume.
C) Predator-mediated coexistence.
D) The value of metapopulations.

Question 31

Scientists have noticed that a nomadic tribes people leave a large native nut out of their diet.Based on optimal foraging theory you might conclude:

A) It is a common food item with high energy
B) It is easily found in areas
C) It has a thick outer shell and therefore a high "handling time"
D) It is a seasonal fruit

Question 32

Parasites are like predators in that they:

A) Can reduce the competitive impacts of otherwise dominant competitors
B) Can reduce the fitness of the organism on which they are preying upon or parasitizing
C) Typically remove one individual from a population
D) There impacts are not at all similar

Question 33

Which terms relate to a process whereby the outcome of ecological interactions between conspecifics shows the consumption rate per individual predator declines with increasing predator density?

A) Mutual interference
B) Transmission
C) Crowding
D) Predator-mediated coexistence

Question 34

Predation and competition

A) Are mutually exclusive ecological processes and do not simultaneously help us understand most population fluctuations
B) Are often overlapping processes that are both needed to explain population changes
C) Overlap more in plant interactions than in animal interactions
D) None of the above

Question 35

When a zero isocline is used in a Lotka-Volterra predator-prey model,it will show that

A) Predator and prey populations are independent
B) Predator and prey populations depend on parasites
C) Predator and prey populations are mutually exclusive
D) Predator and prey populations are linked, with predator abundance tracking that of the prey

Question 36

In which interaction would it be typically be easiest to see the fitness impacts on the negatively affected individual?

A) Predation
B) Parasitism
C) Grazing
D) Symbiosis

Question 37

A Type II survivorship curve:

A) Shows that mortality is constant
B) Shows that younger individuals die sooner than older individuals
C) Is typical of seeds
D) Shows that the risk of mortality is the same regardless of age

Question 38

Optimal foraging theory is based on the following:

A) Handling times of prey items
B) Search time for prey items
C) Energy available in prey items
D) All of the above

Question 39

You notice that smaller field caught lizards tend to have more mites than larger lizards.It is safe to conclude:

A) Small lizards are more vulnerable to parasites than large lizards
B) It is difficult to conclude anything without doing a follow up experiment
C) Small lizards have growth stunted as a result of parasites
D) Mites make it difficult for small lizards to find food

Question 40

Data to test the impacts of mites on lizards might include

A) Correlating number of eggs laid by females with the number of mites each female hosts
B) Experimentally manipulating mite numbers on lizards and subsequently follow lizard growth
C) Measuring lizard weight gain before and after mite removal
D) Adding food supplements to the diets of all lizards

Question 41

When high energy prey are common you might predict predators _____________.

A) Become more choosy about which parts of the prey they consume
B) Become less choosy by consuming the entire prey
C) Become generalists
D) Move from patch to patch quickly

Question 42

A species that is found on several small islands is less likely to go extinct than if it were just found on one island.This is best explained by the __________ concept

A) Competitive exclusion
B) Predator dominated
C) Metapopulation
D) Crowding

Question 43

Hummingbirds actively and aggressively defend rich sources of nectar.This food source is not limited,yet the consumption rate per individual is reduced.This might be due to__________.

A) Lotka-Volterra predator-prey relationships
B) Mutual interference and hummingbirds spending more time defending sources of nectar
C) Crowding, which tends to dampen intraspecific competition
D) Mutual interference and hummingbirds spending more time searching for sources of nectar

Question 44

The term aPN in the Lotka-Volterra predator prey models denotes _______

A) The consumption rate of prey
B) The overall impact of prey on predators
C) The change in predator numbers
D) The zero isocline for prey

Question 45

Some ants are known to lock their mouthparts onto the very top of grass blades when they are infected by a certain parasite.This might be an example of_________

A) Altered host behavior to enhance parasite transmission
B) Altered host behavior to enhance foraging
C) A behavior unrelated to the parasite
D) None of the above

Question 46

The Lotka-Volterra predator-prey models demonstrate ______________?

A) Why prey will typically go extinct in most situations
B) Why predator numbers often lag behind prey numbers
C) Why prey numbers often lag behind predator numbers
D) That predator and prey populations are unrelated

Question 47

A spider can be thought of as _______.

A) An active predator
B) A predator with low handling times
C) A predator that specializes on one species of prey
D) A sit and wait predator

Question 48

When predation interrupts competitive exclusion it is said to result in __________________.

A) Prey population cycles
B) Predator-mediated coexistence
C) Predator-induced competition
D) Prey-mediated predator population cycles

Question 49

The following is a behavior that might be observed in a predator exhibiting optimal foraging: ________

A) Dropping high energy food from its diet
B) Dropping common food items from its diet
C) Leaving a patch of prey when encounter rates get low
D) Leaving a patch when prey densities remain constant

Question 50

The defenses of turtles and armadillos are likely designed to _______:

A) Lower energy available to potential predators
B) Lower handling times of potential predators
C) Increase handling times of potential predators
D) None of these