APES Chapter 4

The risk of introducing a natural enemy to control an invasive species is that

the natural enemy might also become an invasive pest

Despite the loss of grasses in African savannahs resulting from competition from the invasive Sodom apple, elephants may help restore savannah communities because

they eat the Sodom apple preferentially, which is toxic to most other species

The relationship between the dung beetles and the disease-carrying flies is a type of

interspecific competition

Which of the following about parasites is true?

They may live inside or outside of their host

If the climate of an environment is rapidly changing, which one of the following organisms would most likely go extinct?

a species of fish that only reproduces asexually

A grasshopper population in a prairie is limited in large part by the number of birds in the region. Following a hurricane that killed many of the birds, the grasshopper population exhibits exponential growth. This happens because the grasshoppers experienced

a steady biotic potential but suddenly decreased environmental resistance

Density-independent factors such as earthquakes and hurricanes are

abiotic factors that are not involved in maintaining a population near its equilibrium

Walking through a national park, you step off a well-marked trail to take a photograph and accidentally trample a rare orchid. This is an example of

amensalism

Many strategies have been used to control leafy spurge, including the deliberate introduction of different species of flea beetles that feed on leafy spurge. Each flea beetle female may lay about 200 eggs in her one-year life span. In places where flea beetle introductions have quickly established large populations that have grown and stabilized, the population growth of these beetles most likely looked like which of these on a graph?

an s-shaped curve

Introduced alien species that cause the most harm are those that

become invasive

Along the shoreline of a pond, Canadian geese, American toads, and grass frogs search for food while bluegill and bass prey on small fish in the shallow water. These species, living and feeding in this particular location, represent one

community

In an ecosystem with many similar species, we typically find

competitors using different resources to minimize interspecific competition

The introduction of invasive North American ctenophores into the Black Sea and the Sea of Azov has

decimated fisheries because the invasive species competes for food with commercial fish species

In its evolutionary sense, fitness reflects the ability to respond to

develop a comprehensive survival strategy (niche) for maintaining a sustainable population

In short, different selective pressures in closely related species, as in Darwin's Galapagos finches, will produce

different adaptations

Leafy spurge has spread completely across many U.S states. If left uncontrolled in these states, leafy spurge populations will

encounter environmental resistance factors and eventually reach their carrying capacity

Plants such as leafy spurge can double their population size every year in part because of their efficient production of large amounts of seeds. Populations that can double every year, such as leafy spurge,

exhibit exponential growth as they spread to new regions

Some beetles escape from a ship and fly to a small island covered with grass but with no trees or beetle predators. As the beetles feed, they destroy all the grasses. But with abundant food, the beetle population soars, doubling in size every month. After about a year, the population crashes as thousands of beetles have destroyed almost all of the plants and there is little left to feed the large population. This scenario best illustrates

exponential growth followed by a population crash

Darwin and Wallace discovered natural selection without knowledge of an important field of biology that is very much a part of biological evolution. What essential part of biological evolution was poorly understood when they first presented natural selection to the world?

genetics and DNA

Introduced invasive species are a growing problem primarily because of

global trade and travel

A keystone species

has a disproportionately large impact on the stability of an ecosystem

A population would be expected to grow if

immigration increased and deaths and emigration decreased

In general, it is rare for a parasite to

kill its host

Genetic diversity in a species does not arise from

lack of resources and unfavorable climate

The relationships among elk predators represent

interspecific competition

The unusual organisms living in Australia have evolved primarily because of

long term isolation of the continent

A population of bullfrogs in a pond produces many thousands of eggs each spring that hatch out into tadpoles. However, only about 1% of the tadpoles survive to reproduce. This population of frogs is experiencing

low levels of recruitment

New genetic traits upon which natural selection can act usually arise from

mutations and crossover

Adaptation in populations takes place in response to

only the selective pressures they currently experience

resource partitioning

reduces interspecific competition and increases species diversity in the community

Territoriality

reduces intraspecific fighting and ensures adequate resources for some members of a species

Two species have separate ranges but use the same food resources. However, their ranges overlap in one area. It is found in the area of overlap that the species have evolved separate anatomical specializations that reduce interspecific competition for food. This is an example of

resource partitioning

Newly formed species typically have experienced different

selective pressures

If organisms are unable to generate enough genetic diversity to survive in a changing environment, they

sometimes go extinct

The drastic reindeer population changes on St. Matthew Island appears to have ultimately been caused by

the absence of any predators

In an ecosystem, the elimination of one new species by another because of direct competition for the same resources is an example of

the competitive exclusion principle

Controlling the Spotted Knapweed reveals

the complex set of relationships in ecosystems can produce unanticipated consequences

The relationship between the moose and wolf populations on Isle Royale reveals

top-down and bottom-up population regulation

Elephant species are declining throughout their range. Factors contributing to their decline include all of the following except

viral and bacterial infections

Which one of the following is a trait that increases the chances of survival for an endangered species?

widespread distribution