ch54 Flashcards
A lake community with four trophic levels suddenly suffers from algal blooms. Using the strategy of biomanipulation, an ecologist may propose __________.
removing fish that eat zooplankton
What are two key factors in species richness equatorial–polar gradients?
Evolutionary history and climate
In an area where soil has not yet formed, called primary succession, the life-forms that are first found are _________.
prokaryotes and protists
When interspecific competition has an outcome called competitive exclusion, _________.
the inferior competitor will be eliminated
Under which of the following circumstances would interspecific competition be most obvious?
When a nonnative organism is introduced to a community
_________ is used to compare the diversity of communities across time and space.
Shannon diversity
The order of the stages of primary succession beginning with glacial retreat as seen at Glacier Bay, Alaska, are ________.
Pioneer, Dryas, Alder, and Spruce stages
Certain species of acacia trees in Central and South America have hollow thorns that house stinging ants, which attack anything that touches the tree. The ants feed on nutrients produced by the acacias. This is an example of __________.
mutualism
The flower fly resembles a honeybee, but the flower fly has no stinger. This is an example of __________.
Batesian mimicry
A species of malaria-carrying mosquito lives in a forest in which two species of monkeys, A and B, coexist. Species A is immune to malaria, but species B is not. The malaria-carrying mosquito is the chief food for a particular kind of bird in the forest.
If all these birds were suddenly eliminated by hunters, which of the following would be an immediately observable consequence?
Increased mortality in monkey species B
A leech that attaches itself to a swimmer is an example of __________.
an ectoparasite
The relationship between an organism and individuals of other species in a community involves _________.
interspecific interactions
Facilitation is _________.
an interaction where species have positive effects on the survival and reproduction of other species without necessarily living in the direct and intimate contact of symbiosis
Plants ________ to protect themselves from herbivores.
use chemical toxins
A diagram of the trophic relationships of a community showing who eats whom is called a(n) __________.
food web
_________ is the tendency of characteristics to diverge more in sympatric than in allopatric populations.
Character displacement
What is the key difference between a dominant species and a keystone species?
While dominant species are the most abundant, keystone species exert control through important roles or niches.
Succession of communities occurs because __________.
each existing community changes the environment
The sum of a species’ use of the biotic and abiotic resources in its environment is called __________.
its ecological niche
The poison-arrow frogs Dendrobates of tropical America are all brightly colored and have very similar patterns. Although each species is distasteful to predators and all possess toxic skin secretions, some of the species live quite separate from the others.
The adaptive relationship among these species is best termed __________.
Müllerian mimicry
Flounder is a type of fish that looks like the seafloor. This is an example of __________.
cryptic coloration
Similar species can coexist in a community by using _________.
resource partitioning
Commensalism is ________.
an interaction between species that benefits one of the species but neither harms nor helps the other species
In the North Pacific, sea otters are keystone predators. A reduction in their numbers has resulted in what changes in the marine community?
Decreased community diversity
