Chapter 53: Population Ecology (Mastering Biology & Dynamic Study Module)
Which equation determines the death rate in year 0-1? (This value is marked with a "?" in the table.)
(80-64)/80=0.200
Which factors have permitted the human population to continue increasing despite using nonrenewable resources at an unsustainable rate? Select all that apply.
- Improvements in medical care - Expansion of high-density urban areas
For a species with a Type II curve, less than ____% of individuals survive for 50% of the maximum life span.
10
Which equation determines the proportion of ground squirrels alive at the start of year 1-2? (This value is marked with a "?" in the table.)
64/80 = 0.800
A particular environmental change causes the deaths of 25 individuals in a herd of 100 wild horses, and it kills 50 individuals in a herd of 200 horses. In this case, the growth of a wild horse population is most likely limited by __________. (Assume that the two herds are found in territories of equal size.)
A density-independent factor
Chimpanzees have a relatively low birth rate. They care for their young, and most chimps live a long life. The chimp survivorship curve would look like ___________.
A relatively flat line that drops steeply at the end
A graph that plots the numbers of individuals who are alive at particular ages is called _________.
A survivorship curve
Earth is not filled to the brim with elephants, or ants, or ferns, or geckos. What prevents a population from growing forever? Many different factors limit population growth. Some of these factors are density-dependent, and others are density-independent. Drag a label under each graph to indicate whether it shows density-dependent population regulation or density-independent population regulation. Labels may be used once, more than once, or not at all.
A: Density-dependent birth rate B: Density-dependent death rate C: Density-dependent birth rate D: Density-independent death rate
Investigate the differences between these two types of population growth by completing the table below. Drag the labels onto the table to identify the characteristics of each type of population growth. Labels can be used once, more than once, or not at all.
A: Exponential growth B: Logistic growth C: Abundant resources D: Limited resources E: Faster as population size increases F: Slows as population size increases G: No limit to population size H: Carrying capacity I: Isabela Island geckos J: Daphne Major geckos
The figure below shows the logistic growth of a hypothetical population of animals. Drag the labels to their appropriate locations on the graph.
A: K B: N C: Time D: K-selection predominates E: R-selection predominates
In a population of 1,000 elephants, how many individuals would survive for 50% of the species' maximum life span?
About 100
Oyster populations are primarily, if not exclusively, composed of _____.
Adults
Look closely at the scale on the y-axis. What number would be represented by the point midway between the tick mark labeled 10 and the tick mark labeled 100?
Approximately 32
A population that grows rapidly at first and then levels off at carrying capacity can be modeled __________.
By a logistic equation
According to this graph, species that exhibit a Type III curve typically produce large numbers of offspring.
Cannot be determined from this graph
Is the following statement supported or not supported by the data shown in the graph? The maximum life span of Albertosauruswas about 100 years.
Cannot be determined from this graph
The maximum population size that a particular environment can sustain is called the _________.
Carrying capacity
Organisms that live in a homogenous abiotic environment and cooperate to avoid being eaten would likely show a(n) __________ pattern of dispersion.
Clumped
Which of the following would most likely be an example of a density-independent factor limiting population growth?
Daily temperature extremes
The difference between density and dispersion is that __________.
Density is the number of individuals of a population in a unit area whereas dispersion is the pattern of spacing of individuals of the population
The concept that summarizes the aggregate land and water area required by each person to produce all resources he or she needs and absorb all waste he or she produces is called the _________.
Ecological footprint
Which of these organisms has a survivorship curve similar to that of humans?
Elephants
Rank the population sizes (N) from fastest to slowest growth. If two population sizes have the same growth, overlap them.
Fastest Growth - N = 12500 - N = 1000 & N = 1500 - N = 750 - N = 500 - N = 250 Slowest Growth
Which of these organisms has a survivorship curve similar to that of oysters?
Grasses
Life tables typically follow the fate of a cohort, a __________.
Group of individuals who are the same age
Assuming that r has a positive value, in the formula dN/dt = rmaxN (KN)/K, the factor rN tends to cause the population to __________.
Grow increasingly rapidly
A population that is growing logistically __________.
Grows fastest at an intermediate population density
The difference between immigration and emigration is that _________.
Immigration is the influx of new individuals from other areas whereas emigration is the movement of individuals out of a population
What is represented on the x-axis of this graph?
Individuals' life spans as a percentage of the maximum life span for the species
A dog gives birth to three puppies one year. Three years later, she gives birth to six puppies. Which type of life history pattern is characteristic of this organism?
Iteroparity
__________ is reproduction where adults produce offspring over many years.
Iteroparity
For a hypothetical mouse population, determine whether the actions described will increase K, decrease K, or not affect K. Drag each statement to the appropriate bin.
K Increases: - A main competitor for food is eliminated, increasing food availability - An abandoned building creates more nesting areas K Decreases: - Wetlands are drained, decreasing the amount of available water - A species with the same food requirements is introduced A parking lot is built, shrinking the habitat No Effect on K: - Offspring live longer
Life history traits that are favored at high population densities are known as _________.
K-selection
A newly mated queen ant founds a nest in an unoccupied patch of suitable habitat. Assuming that no disasters strike the nest, which of the following types of equations is likely to best describe the population growth of the new colony?
Logistic
The selective pressures of having a large brood of offspring to care for, as in the kestrel experiment, _________.
Lower the survival rates of the parents
For species with a Type III curve, most individuals reach the maximum life span.
Not supported
Is the following statement supported or not supported by the data shown in the graph? The mortality rate of Albertosaurusdinosaurs aged between 25% and 50% of their maximum life span was far greater than the mortality rate of dinosaurs that reached 75% of their maximum life span.
Not supported
What is shown on the x-axis?
Percentage of the maximum life span of a species
A group of individuals of a single species living in the same general area is called a _________.
Population
Fluctuations in the numbers of individuals in a population from year to year are called _________.
Population dynamics
Which of these species typically has a mortality rate that remains fairly constant over an individual's life span?
Robins
_________ describes an organism that reproduces once in its lifetime.
Semelparity
According to the graph, which modern animal has a relatively constant mortality rate throughout its life span?
Startling
In species that exhibit a Type II survivorship curve, individuals are no more likely to die at one stage of the life cycle than another.
Supported
At 50% of maximum life span, how does survivorship for a Type I curve compare to survivorship for a Type III curve?
Survivorship for a Type I curve is nearly 1,000 times as great as survivorship for a Type III curve.
An antagonistic social interaction used to defend a bounded physical space is called __________.
Territoriality
Which of these was the second of the major events that stimulated an increase in the size of the human population?
The Industrial Revolution
Which of these was the first of the major events that stimulated an increase in the size of the human population?
The advent of agriculture
No population can grow indefinitely. The ultimate size of any population is limited by __________.
The carrying capacity of its environment
Which of these was the third of the major events that stimulated an increase in the size of the human population?
The discovery of vaccines and the discovery of antibiotics
Although there are organisms whose life histories fall somewhere between iteroparity and semelparity, life history always represents a trade-off. Why is this?
The energy cost of reproduction is high, so there are not enough resources to reproduce often, produce many offspring, and take care of them.
Which statement regarding the two populations of Belding's ground squirrels is correct?
The second population had a higher proportion alive at the start of year 1-2
Mechanisms of density-dependent selection includes all of the following except _______.
The size of the brood
At 50% of maximum life span, how does the survivorship of Albertosauruscompare to the survivorship of the crocodile?
The survivorship of Albertosaurus is about 100 times greater then that of the crocodile
Why is a percentage scale used for the x-axis rather than actual ages?
This scale allows you to compare species with widely varying life spans on the same graph.
A survivorship curve that represents high death rates for the young is a ________ curve.
Type III
An oak tree produces thousands of acorns, but very few grow into mature oak trees. The oak tree exhibits a __________ survivorship curve.
Type III
Herring gulls fiercely defend the areas around their nests in cliff-top breeding colonies. Within the colony they would show a __________ dispersion pattern.
Uniform
What absolutely essential resource is likely to limit the carrying capacity of Earth for humans?
Water
Life history traits that are favored in uncrowded environments are known as _________.
r-selection
