Chapter 54 Population Ecology Practice Test
Terms in this set (37)
A population is a _____.
group of individuals from the same species that live in the same area at the same time
What is the trade-off between life expectancy and fecundity?
An organism has a finite amount of resources. Investing more resources in reproduction means fewer resources available for survival.
What is the difference between logistic and exponential growth model predictions when population numbers become high?
Both models are the same at low population densities, but when densities are high the logistic model reduces or stops its growth, whereas the exponential ignores density.
A carp has a large number of offspring, but predators eat many of them during the first year of life. Once they survive to maturity, they have few predators. What type of survivorship curve does a carp have and why?
Type III, because carp have a low survivorship initially but a high survivorship once they have matured
What is the logic behind the calculation of the net reproductive rate?
The growth rate of a population is the average number of female offspring that each female produces over the course of her lifetime.
White-tailed deer were quite rare across the northeastern United States approximately 100 years ago, but now their populations are generally considered to be too high. What do you predict has caused this?
Hunting females was prevented, and the intrinsic fecundity rate is actually quite high.
Which factor is one that is used to calculate population growth?
Which population would be most likely to experience exponential growth?
A young population with few individuals
Which of the following statements about exponential growth is true?
In reality, it is not possible for population growth to continue indefinitely.
What are the implications of the fact that the hare population increases greatly when food is high and predators are excluded?
The hare population is controlled by both food supply and the lynx population.
Experiments performed on the bridled goby in coral reefs and song sparrows on Mandarte Island support the hypothesis that density-dependent effects can cause logistic population growth. What conclusions can be drawn from logistic growth models?
Individuals survive better and clutch size increases when the population density is low.
What are population dynamics?
Changes in populations through time and space
Why can metapopulations remain stable over time even if some subpopulations go extinct?
Migration from other subpopulations can reestablish formerly extinct subpopulations.
To understand the history of a human population and predict its future, biologists must do more than tally the overall number of individuals. Which of the following descriptions is an inference that can be made from age pyramid models?
Developed nations are more likely to have older men.
Which of the following statements is true about the metapopulation model?
Migration from nearby populations can reestablish populations.
Which generalizations apply to most species endangered by human actions?
They have high juvenile mortality, low adult mortality, and low fecundity.
Under what condition might r, the per-capita rate of increase, approach rmax, the intrinsic rate of increase?
When resources are abundant
Which of the following leads to growth of a population?
In some European countries, the population is declining. In these countries, the net reproductive rate, R0, is _____.
less than one
Which of the following is a constant for a given species?
rmax, the intrinsic rate of increase
An ideal habitat with unlimited resources is associated with
The maximum population a habitat can support is its
Logistic growth involves
Population growth slowing down as the population approaches carrying capacity.
In exponential growth
Population size grows faster and faster as the population gets bigger.
Which of the following would NOT cause population size to decrease?
Increased birth rate
What conclusion can be drawn from the experiments to determine why red grouse populations in Britain experience population cycles?
The population cycles are caused by density-dependent changes in disease rates.
Which of the following statements about age pyramids is true?
Predictions of a population's future take into account such factors as increasing survivorship and fecundity levels that remain the same.
True or false? The growth rate of a certain population increases very quickly for a time and then levels off to zero. The most likely reason that the growth rate leveled off to zero is that the environment reached its carrying capacity.
The average age of childbearing in country A is 26, whereas the average age in country B is 30. In each country, the average number of offspring per woman is 3. Which of the following statements about the population growth rate in each country must be true?
It is not possible to compare the population growth rates of countries A and B.
In 1970, the average age of childbearing was 28, and the average number of offspring per woman was 3 in a certain country. In 1980, the average age of childbearing was still 28, but the average number of offspring per woman was 2 in that country. If the death rate in the country remained constant during those years, how did the population growth rate change from 1970 to 1980?
The population growth rate decreased.
Which processes increase a population's size?
Births and immigration.
True or false? Factors that determine the intrinsic rate of increase of a population include the age of breeding and the number of offspring produced each year.
Which factor does not affect a habitat's carrying capacity?
Maximum number of individuals in a population.
Which equation represents the logistic growth rate of a population?
ΔN/Δt = rMmaxN [(K-N) / K].
Which of the following statements about density-independent growth is true?
Density-independent growth is also known as exponential growth.
Under which of the following conditions would a population most likely experience exponential growth?
Young populations with few individuals.
Which of the following statements about a population experiencing logistic growth is true?
If N is greater than K, the population will shrink.