IBIO 355 Exam #1 (For Real This Time) Study Guide

A population is defined as _blank​_.

A) all the members of a species and the area they live in

B) members of a species living in a defined area

C) individuals living in an isolated area

D) members of several species living in a defined area

B: members of a species living in a defined area

The greatest threat to biological diversity and integrity of the biosphere is the growth of _blank​_ populations.

A) invasive species

B) crop pest

C) human

D) pathogen

C: human

Which of the following non-demographic characteristics best describes the general characteristics of populations?

A) symbiotic

B) evolutionary

C) spatial

D) temporal

C: spatial

There are limits to how much organisms can compensate for _blank_ variation.

Environmental, temporal, or spatial

To an ecologist, niche summarizes the environmental characteristics that influence the _blank​_, _blank​_, and _blank​_ of a species.

A) reproduction

B) growth

C) ecosystem

D) survival

E) diversity

A, B, and D; reproduction, growth, and survival

What type of niche is more restrictive because it includes interactions with other species in addition to environmental factors?

A) fundamental niche

B) Grinnell's niche

C) realized niche

C: realized niche

The larvae of Balanus are found at _blank​_ levels of the intertidal zone compared to Chthamalus.

A) lower

B) higher

C) similar

C: similar

In his experiments with barnacles, Connell looked at the effects of competition by transplanting _blank​_ to the lower intertidal zone.

A) adult Chthamalus

B) adult Balanus

C) larval Chthamalus

D) larval Balanus

A: adult Chthamalus

When talking about the distributions of organisms, "large-scale" versus "small-scale" refers to _blank​_ change relative to the size of the organism.

A) phenotypic

B) evolutionary

C) environmental

D) climate

C: environmental

Animals living near watering holes would be an example of a _blank​_ distribution.

A) regular

B) basic

C) random

D) clumped

D: clumped

What happened between creosote bushes that was thought to be the cause of their pattern of distribution?

A) competition

B) grazing

C) erosion

D) soil deposition

A: competition

Research prior to Phillips and MacMahon indicated that creosote bush distribution was driven by _blank​_.

A) soil

B) slope

C) temperature

D) moisture

D: moisture

During the course of their growth, Phillips and McMahon found that the distribution pattern of creosote bushes _blank​_.

A) remained constant with time

B) was independent of time

C) fluctuated randomly over time

D) changes as they grow

D: changes as they grow

The number of individuals per unit area is known as _blank​_.

A) demographics

B) rarity

C) density

D) abundance

C: density

A proposed explanation for the distribution of creosote bushes is _blank​_ competition.

A) pollinator

B) grazer

C) branching

D) below ground

D: below ground

In support of their hypothesis, Brisson and Reynolds found that the overlap of roots between adjacent plants was _blank​_ the expected overlap if the plants simply had a circular pattern of root growth.

A) equal to

B) greater than

C) less than

C: less than

Areas of high density for a species identified in the annual Christmas Bird Count are referred to as _blank​_.

A) hot spots

B) roosting commons

C) critical centers

D) modal areas

A: hot spots

Connell found that the upper limits to the distributions of the intertidal barnacles are determined by susceptibility to _blank​_.

A) predation

B) desiccation

C) wave energy

D) microhabitats

B: desiccation

From its name, you would expect fish crows to have hot spots near coastal locations.

A) True

B) False

A: True

Brown et al. looked at bird distributions when they were in their _blank​_ grounds.

A) breeding

B) wintering

C) foraging

D) migratory

A: breeding

Large creosote bushes appear to have a(n) _blank​_ distribution.

A) clumped

B) regular

C) ambiguous

D) random

B: regular

In trying to explain the distribution patterns of creosote bushes, Phillips and MacMahon mapped sites that varied in _blank​_ and _blank​_ but were similar in _blank​_ and _blank​_.

A) temperature; soil; slope; precipitation

B) slope; soil; precipitation; temperature

C) temperature; precipitation; soil; slope

D) slope; precipitation; temperature; soil

C: temperature; precipitation; soil; slope

Root et al. found that over half the bird populations occurred in less than 25% of the sites sampled. This would indicate that the birds had a _blank​_ distribution.

A) binary

B) random

C) regular

D) clumped

D: clumped

In a biodiversity survey of the Great Plains, you would expect to find _blank​_ numbers of field mice compared to bison in a defined sample area.

A) lower

B) greater

C) irrational

D) similar

B: greater

In Damuth's study, population densities and body sizes spanned _blank​_ orders of magnitude.

A) 7

B) 2.718

C) 5

D) 3

C: 5

Peters and Wassenberg expanded upon Damuth's research on density and body size by looking at which of the following in addition to herbivorous mammals?

A) deciduous trees

B) birds

C) herbs

D) invertebrates

E) poikilothermic vertebrates

B, D, and E; birds, invertebrates, and poikilothermic vertebrates

In studying plant population densities, White found that densities _blank​_ increasing "body" size.

A) are independent of

B) decrease with

C) increase with

B: decrease with

Match competition, amensalism, mutualism, and neutralism with the following: +/+, -/-, 0/0, 0/-

Competition: -/-

Amensalism: 0/-

Mutualism: +/+

Neutralism: 0/0

One of the criticisms of Root's analysis of bird distributions was that it only looked at data from a time when the birds were on their _blank​_ grounds.

A) wintering

B) breeding

C) migratory

D) summer

A: wintering

What happened between creosote bushes that was thought to be the cause of their pattern of distribution?

A) grazing

B) erosion

C) soil deposition

D) competition

D: competition

In what type of symbiotic relationship do both members benefit?

Mutualism

In what symbiotic relationship does one member benefit while the other is either harmed or unaffected?

Parasitism

In what symbiotic relationship does one member benefit while the other is neither benefited nor harmed?

Commensalism

If two species interact and one is harmed with no impact on the other, the interaction is classified as _blank​_.

Amensalism

Interference competition involves _blank​_ interaction between individuals.

Direct

A scientist doing research on competition between crows and vultures would be studying _blank​_ competition.

Interspecific

In Toumey's experiments investigating competition, the purpose of trenching around the perimeter of plots was to _blank​_.

A) channel water away from the trees

B) establish control plots

C) eliminate potential root competition

D) mark the boundaries of plots

C: eliminate potential root competition

The struggle between individuals for a limited resource is a form of _blank​_ competition for that resource.

Exploitative

Which of the following are considered to be characteristics of populations?

A) metabolic rate

B) growth rate

C) spacing

D) species diversity

E) density

B, C, and E; growth rate, spacing, and density

Behavioral, physiological, and anatomical characteristics interact with the _blank _ to influence the geographical distribution of populations.

Environment

The difference between the realized and the fundamental niche is the additional requirement of _blank_ factors as part of the definition of the _blank_ niche.

biotic; realized

On a mountain slope, where environmental change occurs quickly with changes in elevation, a "small-scale process" would be a _blank​_ land area than an area where environmental change was more gradual.

A) similar

B) larger

C) smaller

D) equal

C: smaller

Grosholz, in his competition experiments, found that isopods grown at higher density had reduced _blank​_ compared to those grown at lower densities.

A) survivorship

B) development time

C) fecundity

D) mortality

A: survivorship

In Tilman's experiments with grass, plants grown at higher densities had _blank​_ biomass per plant than those grown at lower densities.

A) greater

B) lower

C) similar

B: lower

Under self-thinning, plant populations _blank​_ as they grow older.

A) lose mass

B) produce fewer leaves

C) become less dense

D) produce fewer branches

C: become less dense

Self-thinning is the result of _blank​_ competition.

Intraspecific

In the "−1/2 self-thinning relationship," the "−1/2" refers to the _blank​_ of the line when plotting the log of the plant biomass against the log of plant density.

A) y-intercept

B) length

C) slope

D) x-intercept

C: slope

The difference between the two self-thinning rules is that the "−1/2 rule" uses total plant biomass, while the "−3/2 rule" uses _blank​_.

A) average weight of the individual plants

B) total leaf biomass of all the plants

C) total root biomass of the individual plants

D) maximum plant biomass of the largest plant

A: average weight of the individual plants

Denno and Roderick proposed that the effects of the increased competition between planthoppers were the result of _blank​_.

A) increased parasitism

B) reduced survivorship

C) reduced food quality

D) increased cannibalism

C: reduced food quality

From the perspective of interspecific competition, we would expect that under the competitive exclusion principle, species living together will generally have _blank​_ niches.

A) different

B) overlapping

C) similar

D) spacious

A: different

The beak sizes of Darwin's finches are related to differences in _blank​_ and those differences result in changes in fitness as some birds were able to out-compete others.

A) age

B) body size

C) habitat

D) diet

D: diet

In Gause's competition experiments with Paramecium species, he was interested in finding out whether _blank​_.

A) the two species would become territorial

B) one species would drive the other to extinction

C) the two species would produce an allopolyploid

D) the two species would engage in niche partitioning

B: one species would drive the other to extinction

Flies and wasps appear to have reduced competition with one another by evolving to prefer different hosts. This process is called _blank_ partitioning.

Niche

Which of the following are considered to be characteristics of models used in ecological research?

A) man-made construct

B) complicated

C) abstraction

D) difficult

E) insightful

A, C, and E; man-made construct, abstraction, and insightful

In the Lotka-Volterra model of competition, which term is added to the logistic equation for a population to reflect the effects of the competitor?

A) α/N

B) αN

C) K−α

D) N/K

B: αN

In the Lotka-Volterra equations, the term α21N1 can be thought of as the number of species _blank​_ that is equivalent to the number of species _blank​_ in depleting resources.

A) 1; 2

B) 2; 1

A: 1; 2

In the Lotka-Volterra equations, coexistence will occur when _blank​_ competition is greater than _blank​_ competition for both species.

A) intraspecific; inhibition

B) interspecific; intraspecific

C) inhibition; interference

D) intraspecific; interspecific

D: intraspecific; interspecific

When a population is greater than its isocline of zero population growth, one would expect the population to _blank​_ over time.

A) increase

B) remain constant

C) decrease

C: decrease

In the Lotka-Volterra model, when the zero growth isoclines for both species cross, which of the following outcomes could you expect?

A) only species 1 wins

B) coexistence of species 1 and 2

C) either species 1 or 2 wins

D) only species 2 wins

B or C; coexistence of species 1 and 2 / either species 1 or 2 wins

When the Lotka-Volterra competition model predicts coexistence, then _blank​_ for species 2.

A) K2 < K1/α12

B) K2 > K1/α21

C) K2 < K1/α21

D) K2 > K1/α12

A: K2 < K1/a12

When grown separately, the carrying capacity for each paramecium species _blank​_ when the bacterial food supply was reduced.

A) decreased

B) increased

C) remained constant

A: decreased

When the two species of paramecium were grown together in Gause's paramecium experiments, reducing the food supply resulted in _blank​_ the time taken for one of the species to go to exclusion.

A) increasing

B) decreasing

C) stabilizing

B: decreasing

At intermediate environmental conditions for beetles, Park found that _blank​_ competition in the interspecific competition.

A) either species could win

B) T. castaneum always won

C) neither species won (coexistence)

D) T. confusum always won

A: either species could win

The priority effect in competition occurs when the species that establishes itself in greater numbers first, wins.

A) True

B) False

A: True

The environmental conditions in which the Tribolium beetles could grow in Park's experiments without other competitors can be considered their _blank​_ niches.

A) coexistence

B) individual

C) realized

D) fundamental

D: fundamental

Grosholz, based on experimental results, proposed that the effects of competition between isopods were the result of _blank​_.

A) increased parasitism

B) increased cannibalism

C) reduced food quantity

D) reduced survivorship

B: increased cannibalism

In Tilman's experiments with grass, the addition of nitrogen to the soil resulted in _blank​_ plant biomass in low-density treatments as compared to high-density treatments.

A) greater

B) correct

C) similar

D) lower

A: greater

Self-_blank​_ is the process where greater amounts of biomass are concentrated in fewer individuals as plants grow.

A) competition

B) renewal

C) determination

D) thinning

D: thinning

In self-thinning, the "thinning" refers to a decrease in _blank​_.

A) population density

B) size of the leaves

C) numbers of leaves

D) size of the plants

A: population density

In the "−3/2 self-thinning rule," we would expect individual plant biomass to _blank​_ as plant density _blank​_.

A) increase; remains constant

B) increase; decreases

C) decrease; remains constant

D) decrease; decreases

B: increase; decreases

How long after snowshoe hares browse on plants will the plant continue to produce chemical defenses? This defense will lower the quality of their food supply.

A) 2 hours

B) 2 days

C) 2 months

D) 2 years

D: 2 years

Which of the following are unrealistic assumptions of the Lotka-Volterra equation?

A) The prey populations are subject to carrying capacities.

B) Changes in the predator population will be instantaneously translated into responses in the prey population.

C) Eternal oscillations on a narrowly defined path will exist.

D) The predator populations are not subject to carrying capacities.

B, C, and D

What is the most immediate consequence of an increase in the snowshoe hare population?

A) The quantity and quality of their food decreases.

B) New species of predators will immigrate into the community.

C) The predator population increases.

A: The quantity and quality of their food decreases

According to the Lotka-Volterra equation, what is the initial response to an increase in the predator population?

A) an increase in the host population

B) a decrease in the available habitat for the predator

C) a decrease in the host population

C: a decrease in the host population

Which of the following are considered exploitative interactions?

A) Predator-prey

B) Parent-offspring

C) Parasite-host

A and C; predator-prey and parasite-host

Identify the role of a predator in a community.

A) Predators take nutrients from other organisms by killing them.

B) Predators are killed by other organisms in order to provide nutrients to them.

C) Predators take nutrients from other organisms without killing them.

A: Predators take nutrients from other organisms by killing them

Match the Acacia resources "Beltian bodies", "Thorns", and "Foliar nectaries" with the benefits they provide the acacia ant.

A) Source of oils and proteins

B) Living space

C) Source of sugars and lipids

Beltian bodies: A

Thorns: B

Source of sugars and lipids: C

Identify the role of a parasite.

A) to kill and consume the nutrients of another organism

B) to obtain energy from inorganic sources

C) to consume nutrients from another organism without killing it

C: to consume nutrients from another organism without killing it

What term is used to describe agents that induce disease?

Pathogens

Acacia performance is greater when acacia ants are present. When ants are absent, there tend to be _blank​_ herbivorous insects on the plants than when the ants are present.

A) fewer

B) an equal number of

C) more

C: more

Which group of organisms is the dominant herbivore in a forest ecosystem?

Arthropods

Which group of organisms in the Kalka study had an impact on reducing the arthropod density in tropical forests?

A) Birds reduced the arthropod density more than bats.

B) Bats reduced the arthropod density, but birds did not.

C) Birds and bats both reduced the arthropod density.

C: Birds and bats both reduced the arthropod density

Studying how the changing sizes of predator and prey populations vary over time is known as _blank_ dynamics.

Temporal

If the snowshoe hare population is impacted by the sunspot cycles, which population will be most directly impacted because the hares are affected?

A) lynx

B) coyotes

C) pines

D) hawks

A: lynx

Which correlation is correct according to the predator hypothesis? As prey population _blank​_.

A) decreases predator population increases

B) increases the predator population increases

C) increases the predator population will decrease

B

What role do understory shrubs play in the life of a snowshoe hare?

A) The hare's parasites winter in shrubs, allowing the parasites to reinfect the hares in the spring.

B) The shrubs provide cover for the hares.

C) The shrubs provide a food source.

D) The shrubs provide compounds that treat bacterial infections.

B and C

Which of the following are considered generalist predators on the snowshoe hare but can use snowshoe hares as their dominate food source when the hare population is large enough?

A) lynx

B) pythons

C) red foxes

D) coyotes

C and D; red foxes and coyotes

Identify the predators that play the greatest role in influencing the snowshoe hare population.

A) long-tailed weasels

B) lynx

C) red foxes

D) coyotes

B and D; lynx and coyotes

Which statement is correct about the functional response of coyotes and lynx to the increase in the hare population?

A) The coyote population decreased in response to the increase in the hare population, while the lynx population increased.

B) Lynx killed more hares than coyotes while the hare population was increasing.

C) Coyotes killed more hares than lynxes while the hare population was increasing.

C: Coyotes killed more hares than lynxes while the hare population was increasing.

What happened to the hare population when the Krebs research team reduced the predators on the study plot?

A) The hare density declined by half.

B) The hare density tripled.

C) The hare density declined by 25%.

D) The hare density doubled.

D: The hare density doubled

Identify the trophic levels that influence the population cycle of the snowshoe hare.

A) the predators of the hares

B) the hares

C) the types of detritivores within the community

D) the hares' food source

A, B, and D

What was the key to understanding the controls on the snowshoe hare population numbers?

A) identifying the food sources for the hares

B) studying all three trophic levels simultaneously

C) identifying the size of the hare population

D) identifying the predators

B; studying all three trophic levels simultaneously

Mathematical models offer population ecologists an opportunity to manipulate variables that cannot be controlled in the field.

A) True

B) False

A: True

Which animals did Alfred Lotka use to model predator-prey interactions?

A) butterflies

B) sharks

C) moths

D) snowshoe hares

A and C; butterflies and moths

Within the Lotka-Volterra model, what type of growth is assumed for the host population?

A) exponential

B) no growth

C) variable

D) logistic

A: exponential

Within the Lotka-Volterra equation, what opposes the growth rate of the predator population?

A) the number of predator deaths

B) the amount of prey available for the predator

C) the reproductive potential of the predator

D) the amount of available habitat for the predator

A: the number of predator deaths

What is the correct order of events in the life cycle of the adzuki bean weevil?

A) Eggs hatch into pupae that metamorphose into larvae that develop into adult weevils.

B) Eggs hatch into larvae that develop into adult weevils.

C) Eggs hatch into larvae that metamorphose into pupae that develop into adult weevils.

C: Eggs hatch into larvae that metamorphose into pupae that develop into adult weevils.

During which stages of the weevils' life cycle are they parasitized by the hymenopteran wasp?

A) adult

B) larvae

C) eggs

D) pupae

B and D; larvae and pupae

Which statement about the weevil and wasp populations is correct?

A) The weevil population was always smaller than the wasp population.

B) The weevil population was always larger than the wasp population.

C) The weevil population was always equal or larger than the wasp population.

C

What are the consequences of the prey populations in most Lotka-Volterra experiments conducted in a lab? The prey population(s) _blank​_.

A) move out of the study area

B) experiences exponential growth

C) experiences logistic growth

D) go extinct

D: go extinct