Chapter 11 Population Growth Flashcards
A ______ bloom occurs when there is an abundance of sunlight and nutrients to provide ideal growth conditions for organisms such as diatoms.
spring
El Niño can cause a(n) _____ in rainfall on the Galápagos Islands. This, in turn, results in higher seed production, which is a food source for the birds known as Darwin’s _______ (book)
increase
finches
True or false: The only feasible way to study population changes is to use mathematical modeling. Laboratory and natural populations are not well-suited to population growth studies.
false
While lab and natural population studies are not always possible due to constraints such as organism size, reproduction rate, etc., they are most certainly feasible for many organisms.
A population growing at its maximum rate grows ______.
slowly at first, then faster
Insects and other organisms that produce a single generation of offspring each year exhibit a(n) ______ growth pattern.
geometric
Temperate seas and lakes experience a ________ bloom when growth conditions for plankton are ideal. Later in the annual cycle, the plankton populations decline due to competition and ____________.
spring
predation
In the equation for geometric growth, t is ______.
number of time intervals
El Niño brings _______ than average rainfall which results in a(n) ________ of seeds. (book)
higher; abundance
Using the equation for geometric population growth, the number of organisms at t=10 years, where N0=150, and λ = 1.67 would be ______.
25,308
Population growth studies ______.
can involve mathematical modeling, studies of lab organisms, and studies of natural populations
Which of the following are reasons why geometric growth is typically not sustainable over many generations?
There would be a greater demand for nutrients than the available supply.
Organisms might be forced to spread to habitats where they are not ideally adapted.
Plants would likely run low on light leaves.
If an organism has access to unlimited or abundant resources, it will likely reproduce at a ______ rate.
maximum
True or false: According to the equation for exponential growth, the rate of population growth declines as the population size increases.
false
The rate of population growth increases as the population size increases because r is multiplied by N.
A geometric growth pattern is exhibited by populations where successive generations differ in size by a constant ______
ratio
Organisms that exhibit exponential growth show a non-pulsed reproductive pattern where population growth is ______.
a continuous process
Using the equation for geometric population growth, the number of organisms at t=5 years, where N0=100, and λ = 2.13 would be ______.
4,384
In the equation shown, N0 equals the _______ number of organisms.
initial
Geometric growth ______.
cannot be maintained for very many generations in the natural world
In the equation for exponential growth rate, dN/dt is ______.
the rate of population growth
Natural populations may grow at exponential rates for short periods of time in the presence of ______ resources.
abundant
Which of the following organisms could exhibit exponential growth?
Whooping crane
In the equation for exponential growth (Nt=NOert), r is the ______.
intrinsic rate of increase
A study done by Bennett was performed in order to ______.
estimate the growth of postglacial trees in Britain
Exponential growth ______.
assumes a constant rate of per capita increase
The ideal conditions for exponential growth are ______ population densities and ______ environmental conditions.
low; favorable
Pollen records used to estimate the growth of postglacial tree populations in Britain showed ______. (book)
the species studied grew at exponential rates for 400–500 years
The whooping crane population in North America is an example of ________ growth since the 1950s or ’60s, due to reduced hunting and management.
exponential
What type of record was used to estimate the growth of several postglacial tree populations in Britain?
pollen
Does the pattern for the Eurasian collared dove indicate the population grew at an exponential rate from 1955 to 1964? (book)
Yes
What has led to the exponential growth exhibited by the whooping crane in North America?
well-controlled management and protection of an initially small population
Logistic population growth occurs as resources become depleted, growth rate slows and eventually ______
stops
Whooping cranes in North America exhibit exponential growth due to ______.
an effective management regime
protection from hunting
Letter B represents the
time when the population is growing rapidly due to abundant resources.
The slowdown in the population growth of the Eurasian collared dove in Western Europe suggested the population was approaching some environmental limits.
true
Several species of yeast were shown to have a logistic growth pattern by ______. (book)
Gause
The population growth model that incorporates environmental limitations and has the growth rate slow before the carrying capacity is reached is called the
_______ population growth model.
logistic
Which of the following are examples of conditions that contribute to populations ceasing to grow (and therefore reaching their carrying capacity)?
Barnacles having little space to attach.
The sugar supply becoming depleted for yeast.
Which of the following does the letter K represent in the logistic growth model? Select all that apply.
The theoretical maximum population
The carrying capacity
In the logistic equation, rmax ______.
occurs if a species is under ideal environmental conditions
is the maximum rate of per capita increase
The scientist associated with studying the sigmoidal population growth in yeast and protozoa is named ______ (book)
Gause
In the logistic equation, what happens to population growth as N increases toward K?
Population growth slows.
Carrying capacity is likely influenced by resource availability, parasitism, disease, and the availability of ______.
space
Using the diagram as an aid, when does the maximum rate of population increase occur?
At very low population size
In the logistic equation, K is ______.
carrying capacity of the environment
In the logistic equation, dN/dt is equal to the change in
individuals ______ divided by the change in ______ otherwise known as the rate of population change.
individuals
time
Which of the following are typically considered to be density-dependent factors that can effect population growth?
competition
disease
predation
Using the diagram as an aid, what occurs during logistic growth if N < K?
Population growth occurs
Dutch elm disease is an especially virulent pathogen that causes total mortality in infected tree populations. Because the virulence occurs regardless of the number of trees in the area, this is referred to as a(n) ______ effect.
density-independent
If the habitat in the Galápagos Islands was as shown in figure (a), birth rates of finches would likely ______ death rates.
exceed
Abiotic factors, such as extreme temperature changes, are typically referred to as density-
_________ factors that can effect population growth.
independent
Which of the following is true of the data shown in this graph?
During years of low rainfall (<100 mm), cactus finches produce 0–1 clutches of eggs.
At high population densities, more animals are forced to live in less sheltered habitats. If the temperatures are very cold, this may lead to increased mortality. In this case, an abiotic factor is affecting the population in a density- _______ way.
dependent
Peter and Rosemary Grant studied ______.
how wet and dry cycles affect cactus finch populations
How did annual rainfall affect the number of egg clutches produced by cactus finches on the Galápagos Islands?
Higher levels of rainfall resulted in 4–6 clutches per pair.
Cactus finches can cause damage to cactus flowers, such as destroying the stigmas, during the
______ season.
wet
As seen on the graph, when cactus flower availability was high, damage done to the cactus plants by the Galápagos finches was ______.
low
Using the map as an aid, which regions of Earth have generally the lowest human population densities?
very northern and very southern latitudes
Which of the following are true concerning the relationship between the Galápagos Islands cactus finches and the cacti they feed on?
The finches eat insects from rotting cactus pads that fall to the ground.
The finches can consume the cactus flower nectar.
The finches consume pollen from flower buds in the dry season.
What caused the low numbers of cactus flowers on Genovesa Island from 1984 on?
Increased osmotic stress due to sea spray hitting coastal cacti in 1983 (due to El Niño).
Flower damage done by cactus finches.
El Niño caused some cactus plants to be waterlogged in 1983.
Rank the continents from smallest to largest in their percentage of the global population in 2011. Begin with the smallest at the top.
- north america
- europe
- africa
- asia
True or false: Human population densities are highest in the coastal regions of continents.
true
Using the figure as an aid, what does Hungary’s age distribution indicate?
The population is declining.
How is it possible that birth rates equal death rates, yet a population can experience population growth?
Immigration can increase the population size.
According to the graph on the left, global population growth ______.
has at times been greater than exponential rates
Using the figure as an aid, what does Rwanda’s age distribution suggest?
The population is rapidly growing.
Typically, emigration has the greatest impact on population sizes of ______ developed nations.
under
