CHAPTER 40 Flashcards

Which variables define the ecological life history of a species?
A) the age at which reproduction begins, frequency of reproduction, and the number of offspring
for each reproductive episode
B) the ratio of females to males, the length of the breeding season, and the number of offspring
for each reproductive episode
C) the number of offspring produced over a lifetime by a breeding pair and the survivability of
the offspring
D) timing breeding sessions with optimal environmental conditions and the number of offspring
produced during each breeding session
E) the amount of parental care given after birth, the number of reproductive episodes per year,
and the number of years females are capable of producing viable offspring

Which pattern of reproduction is correctly paired with a species?
A) iteroparity—Pacific salmon
B) iteroparity—elephant
C) semelparity—oak tree
D) semelparity—rabbit
E) semelparity—polar bear

In which of the following situations would you expect to find the largest number of K-
selected individuals?
A) a recently abandoned agricultural field in Ohio
B) a shifting sand dune community of south Lake Michigan
C) an old-growth forest
D) South Florida after a hurricane
E) a newly emergent volcanic island

Which of the following is most likely to contribute to density-dependent regulation of
populations?
A) the removal of toxic waste by decomposers
B) intraspecific competition for nutrients
C) earthquakes
D) floods
E) fires

Why do populations grow more slowly as they approach their carrying capacity?
A) Density-dependent factors lead to fewer births and increased mortality.
B) Density-independent factors lead to fewer births and increased mortality.
C) Hormonal changes promote higher death rates in crowded populations.
D) Individuals voluntarily stop mating so that overcrowding does not occur.
E) The incoming energy decreases in populations experiencing a high rate of increase.

Which of the following could be a density-independent factor limiting human population
growth?
A) social pressure for birth control
B) earthquakes
C) plagues
D) famines
E) pollution

6) Which of the following best substantiates why location 3 is an equatorial (tropical) climate?
A) It has a monsoon season during the winter months.
B) It has consistent monthly averages for rainfall.
C) The temperature is high for each monthly average.
D) The temperatures reach 100°F during some months.
E) The temperatures are lower in June, July, and August.

Which statement best explains survivorship curve B?
A) It is likely a species that provides little postnatal care, but lots of care for offspring during
midlife, as indicated by increased survivorship.
B) This curve is likely of a species that produces lots of offspring, only a few of which are
expected to survive.
C) It is likely a species where no individuals in the cohort die when they are at 60-70% relative
age.
D) There was a mass emigration of young to middle-aged individuals in this cohort.
E) Survivorship can only decrease; therefore, this curve could not happen in nature.

What might be the adaptive significance of these unusual forests growing the way they do in
this marginal habitat?
A) Needles are adapted to withstand cold arctic temperatures.
B) Branches are adapted to absorb more CO2 with this displaced alignment.
C) Taproot formation is impossible, so trees developed shallow root beds and easily tilt.
D) Trees are tilted so that snow won’t break them or tip them over.
E) Trees tip so that they do not compete with each other for sunlight.

Imagine that you are managing a large game ranch. You know from historical accounts that a
species of deer used to live there, but they have been extirpated. You decide to reintroduce them.
After doing some research to determine what might be an appropriately sized founding
population, you do so. You then watch the population increase for several generations, and graph
the number of individuals (vertical axis) against the number of generations (horizontal axis). The
graph will likely appear as
A) a diagonal line, getting higher with each generation.
B) an "S," increasing with each generation.
C) an upside-down "U."
D) a "J," increasing with each generation.
E) an "S" that ends with a vertical line.

Which of the following biomes is correctly paired with the description of its climate?
A) savanna–low temperature, precipitation uniform during the year
B) tundra–long summers, mild winters
C) temperate broadleaf forest–relatively short growing season, mild winters
D) temperate grasslands–relatively warm winters, most rainfall in summer
E) tropical forests–nearly constant day length and temperature

A population's carrying capacity
A) may change as environmental conditions change.
B) can be accurately calculated using the logistic growth model.
C) generally remains constant over time.
D) increases as the per capita growth rate (r) decreases.
E) can never be exceeded.

When climbing a mountain, we can observe transitions in biological communities that are
analogous to the changes
A) in biomes at different latitudes.
B) in different depths in the ocean.
C) in a community through different seasons.
D) in an ecosystem as it evolves over time.
E) across the United States from east to west.

According to the logistic growth equation
= r max N
A) the number of individuals added per unit time is greatest when N is close to zero.
B) the per capita growth rate (r) increases as N approaches K.
C) population growth is zero when N equals K.
D) the population grows exponentially when K is small.
E) the birth rate (b) approaches zero as N approaches K.

If the direction of Earth's rotation reversed, the most predictable effect would be
A) no more night and day.
B) a big change in the length of the year.
C) winds blowing from west to east along the equator.
D) a loss of seasonal variation at high latitudes.
E) the elimination of ocean currents.