Transcript Chapter 2

Active Lecture Questions for
BIOLOGY, Eighth Edition
Neil Campbell & Jane Reece
Chapter 54
Community Ecology
Questions prepared by
Eric Ribbens,
Western Illinois University
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
Two-species interactions are classified by the impact
each species has on the other species. Thus, a competitive
interaction is one where the populations of each species
are hurt by the presence of the other species, usually
because each species consumes the same resources.
Niche partitioning enables species to coexist by
a) avoiding direct competition.
b) encouraging mutualistic interactions.
c) providing prey with a place to hide from predators.
d) creating new resources.
e) allowing abiotic factors, such as climate or nutrient
availability, to influence the community.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
What is one difference between the fundamental
niche and the realized niche?
a) The realized niche is larger.
b) The fundamental niche is determined by
competitors.
c) The realized niche is determined by abiotic
resources.
d) If you want to find the species, look in the realized
niche.
e) The difference is called the occupied niche.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
Look at Figure 54.3 in the textbook. Joseph Connell
showed that when Balanus are removed from the
intertidal zone, Chthamalus expand their niche. What
would you predict if he removed Chthamalus?
a) Since Balanus is the superior competitor, it probably would
move up into the space Chthamalus occupied.
b) Since Chthamalus is the superior competitor, it probably
would move down into the space Balanus occupied.
c) Since Balanus is the superior competitor, it probably cannot
live in the high intertidal zone.
d) Balanus would disappear as well, since it preys on
Chthamalus.
e) none of the above
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
Figure 54.4 shows that when two species of finch coexist,
their beak sizes diverge, which is character displacement. If
the two species colonized an island on which there were seeds
of only one size, what would Gause’s principle of competitive
exclusion (page 1199 in the textbook) predict?
a) The finches would hybridize and
become one species.
b) G. fuliginosa would evolve small
beaks, and G. fortis would evolve
large beaks.
c) One of the finch species would
probably disappear from the
island.
d) The plants would evolve seeds
of different sizes.
e) It is impossible to predict the
outcome
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
An obligate mutualism is an interaction in which at
least one species cannot survive without the presence
of the other species; a facultative mutualism is an
interaction that benefits both species but is not
required by either species. One reason facultative
mutualisms are more common is
a) in an obligate mutualism, if the partner becomes extinct, the
obligate mutualist will also become extinct.
b) in a facultative mutualism, if the partner becomes extinct, the
obligate mutualist will also become extinct.
c) in an obligate mutualism, the obligate mutualist is obliged to
support its partner.
d) in a facultative mutualism, neither partner can depend on the
other partner.
e) obligate mutualisms can occur only in tropical environments.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
This graph (Figure 54.10 in the textbook) shows
the effect of soil pH on microbial diversity. One
conclusion you should draw from this figure is
a) the higher the soil pH, the
higher the microbial diversity.
b) the lower the soil pH, the
higher the microbial diversity.
c) microbes eat pH.
d) the scientists couldn’t find
any acidic or basic soils.
e) there appears to be an
optimal pH value for
maximizing microbial
diversity.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
Look at the following figure (Figure 54.13 in the
textbook), which shows a partial Chesapeake Bay
food web. If sea nettles disappeared, this figure
predicts that
a) there would be fewer fish
eggs.
b) there would be more striped
bass.
c) there would be fewer
zooplankton.
d) striped bass would have
less food to eat.
e) sea nettles would reinvade
from the ocean.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
Look at the following graph (Figure 54.15 in the
textbook). Robert Paine removed Pisaster, an uncommon
starfish, and measured species diversity. He found species
diversity dropped dramatically when Pisaster was not
present. From this, we can conclude that
a) uncommon species are more
important than common
species.
b) predators are more important
than prey.
c) Pisaster probably preferred to
consume the dominant
competitors.
d) Robert Paine’s experiment
was poorly designed.
e) removing one species always
hurts the community.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
Disturbance is an important component of
succession because it
a) removes keystone species.
b) changes the biome from one kind to another.
c) introduces invasive species.
d) is associated with humans.
e) tends to promote earlier-successional stages.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
The fact that vertebrate species richness is
correlated with potential evapotranspiration
indicates that
a) temperature is more important than rainfall.
b) humidity is more important than temperature.
c) humidity is more important than rainfall.
d) rainfall is more important than temperature.
e) mammals prefer stable climates.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
The intermediate disturbance hypothesis predicts
that
a) most disturbances are intermediate in intensity.
b) species richness is highest when disturbances are
intermediate.
c) most communities are at an intermediate stage of
succession.
d) intermediate disturbances maximize competitive
exclusion.
e) because species richness corresponds to
geographic area, intermediate disturbances increase
species richness.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.