Bio Ch. 36 , 37, 38
Which of the following is an example of a population?
all of the students in your classroom
Assume that there are five alligators per acre in a swamp in northern Florida. This is a measure of the alligator population’s
The pattern of distribution for a certain species of kelp is clumped. We would expect that the pattern of distribution of snails that live on the kelp would be
The density of Douglas firs in an old-growth forest is estimated by counting the Douglas firs in four sample plots of 1 hectare each. The number of fir trees in the plots is 10, 12, 7, and 11, respectively. What is the estimated density of the firs in the forest?
10 trees per hectar
A survivorship curve is a
graph that plots an individual’s likelihood of being alive as a fucntion of age.
A Type I survivorship curve is associated with which of the following life history traits?
parents providing extended care for their young.
A survivorship curve that involves producing very few offspring, each of which has a high probability of surviving, is typical of
The maximum number of individuals a habitat can support is called its
Consider a stable frog population living at carrying capacity in a pond. If an average female produces 6,000 eggs during her lifetime and an average of 300 tadpoles hatch from these eggs, how many of these tadpoles will, on average, survive to reproduce.
A population of fungi in a yard produces 10 mushrooms in year 1, 20 in year 2, and 40 in year 3. If this trend continues, by year 5 there will be _______ mushrooms?
A newly mated queen ant establishes an ant nest in an unoccupied patch of suitable habitat. The population of the nest grows quickly at first, then levels off at carrying capacity. Which of the following types of equation will best describe its population growth?
A test tube is inoculated with 1×10^3 cells of a bacterial strain that has a generation time of 30 minutes. The carrying capacity of the test tube for this strain is 6×10^9 cells. What will the bacterial population be after 90 minutes of culturing?
If a population has a birth rate of 40 individuals per 1,000 per year and a death rate of 30 individuals per 1,000 per year, how will the population change each year? (Assume that the population is below carrying capacity and that there is no immigration or emigration).
It will increase by 1%
A human population will achieve zero population growth if
couples have an average of about 2.25 children each (to account for some children who do not survive to reproduce)
The death by bubonic plague of about one-third of Europe’s population during the fourteenth century is a good example of
a density-dependent effect
A tidal wave wipes out the entire population of mice living on an island. This is an example of
the effects of abiotic factors
In the logistic growth model, as population size increases, birth rates
decline and/or death rates increase
Which of the following is most clearly a case of density-dependent population regulation?
a dangerous new flu strain that is transmitted among humans by sneezing
In terms of population dynamic, what is “boom-and-bust” cycling?
a situation in which a population moves back and forth between rapid growth and decline
An ecologist hypothesizes that predation by a particular owl species is the major factor controlling the population of a particular rabbit species. If this is the case, which of the following population effects could be expected in this rabbit-owl pair?
An increase in the owl population should cause a fall in the rabbit population
An r-selected species typically
has an advantage in habitats the experience unpredictable distubances
Which of the following organisms best illustrates K-selection?
a polar bear producing one or two cubs every three years
Guppies from Trinidad form two distinct populations that differ in several life history traits that appear to relate to the local predator populations, pike-cichlids or killifish. Which of the following experiments would test the heritability of these traits?
Raise both populations without predators to see if they maintain their life history traits
A demographic tool used to predict a population’s future growth is
Which of the following statements about human demographic trends is true?
A human population in which women reproduce at a later age will experience slower population growth.
The human population on Earth is expected to reach 9.5 million people by
An ecological footprint
is a means of understanding resource availability and usage
A community is composed of
potentially interacting populations of different kinds of organisms
An owl and a hawk both eat mice. Which of these describes the relationship between a hawk and an owl?
When two different populations in a community benefit from their relationship with each other, the result is called
When a crocodile eats a fish, the interspecific interaction between the two could be expressed as _______for the crocodile and _____for the fish.
The sum total of a population’s use of the biotic and abiotic resources of its habitat constitutes its
In an ecosystem, you would expect to find interspecific competition between
populations of two species that occupy the same niche
If an overlap develops between the ranges of two closely related species, and if the species occupy the same niche in the zone of overlap, what will probably happen in the zone of overlap?
One of the species will take over most or all of the zone of overlap
Dinoflagellates are important to coral and coral-dwelling animals because they
produce energy that is used by coral animals through photosynthesis
Camouflage typically evolves as a result of
Some herbivore-plant interactions evolved through a series of reciprocal evolutionary adaptations in both species. The process is called
On Earth, most organic molecules are produced by
In a food chain consisting of phytoplankton—-zooplankton—fish—-fisherman, the fisherman are
Organisms that digest molecules in organic material and convert them into inorganic forms are
In a certain ecosystem, field mice are preyed on by snakes and hawks. The entry of wild dogs into the system adds another predator of the mice. Of the following, the most likely short-term result of this addition is
a reduction in numbers of mice
Which of the following statements regarding food webs is true?
Several species of primary consumers may feed on the same species of producer
The number of species in a community is called the
We expect that a keystone species that is a predator will
maintain the species diversity in a community
During ecological succession, the species composition of a plant community generally
changes gradually because each species responds differently to the changing environment
When a New England farm is abandoned, its formerly plowed fields first become weedy meadows, then shrubby areas, and finally forest.This sequence of plant communities is an example of
Biological control is defined as
the intentional release of a natural enemy of a pest population
The flow of ______into ecosystems occurs in one direction only, while _____ are recycled within the ecosystem itself.
About how much of the energy in the producers of an ecosystem will be available to secondary consumers in the ecosystem?
You want to do all that you can to safeguard the environment by preserving energy. One simple thing that you can do is to eat a diet consisting only of organisms that are
Carbon mainly cycles between the biotic and abiotic worlds through the processes of
cellular respiration and photosynthesis
Which of the following statements about the phosphorus cycle is true?
Guano can be used by farmers to add phosphorus to the soil
Denitrifying bacteria convert_____to_______.
Eutrophication of a lake could occur if
phosphate-rich detergents were dumped into the lake
The primary goal of conservation biology is to
counter the loss of biodiversity
the genetic diversity within and between populations of a species
The three greatest current threats to biodiversity, in order starting with the greatest, are
habitat loss, invasive species, and overharvesting
To decrease pollution from sulfur, your local power plant built very tall smokestacks. The ultimate consequence of this would most likely be
to create an environmental problem at a distance from the power plant
Which of the following is a likely consequence of the thinning of the ozone layer?
increases in skin cancer
You spray your lawn with a pesticide. The concentration of the pesticide in the tissues of the grass on your lawn is 10^-6 parts per million (ppm). Grasshoppers eat the grass and are in turn eaten by rats, which are then eaten by owls. At each successive trophic level, the concentration of pesticides increases. The term for this process is
Greenhouse gases include
carbon dioxide and methane
Average global temperature has risen____over the past 100 years.
0.8 degrees C
CO2 in the atmosphere is absorbed by______and converted into biomass.
Scientists worry that global warming will result in the oceans
becoming more acidic
One way in which populations and species have been responding to climate change is by
shifting their distribution
The ability to change phenotype in response to local environmental conditions is called
Some populations, especially those with high genetic variability and short life spans, may avoid extinction as the climate changes through
has allowed for the re-introduction of many species to areas from which they had disappeared
Which of the following statements about movement corridors is true?
Movement corridors can connect otherwise isolated habitat patches
Habitats with many edges
often result from human activities
Small area that are home to a large number of threatened species and an exceptional concentration of species found nowhere else on Earth are called
biodiversity hot spots
Species found in only one place on Earth are called______species.
Most biodiversity hot spots are found in ______regions.
About one-third of all animal and plant species are concentrated on ______of Earth’s land.
One result of Costa Rica’s commitment to conservation is that
ecotourism generates many jobs and brings in a significant fraction of the country’s revenue
The introduction of wolves into Yellowstone National Park in 1991 resulted in
ecological changes involving at least 25 species
The Yukon to Yellowstone Initiative is a plan to
connect parks in the United States and Canada with protected corridors where wildlife can travel safely
If wolves were now removed from Yellowstone National Park, we would expect that
elk populations would increase
The aspect of conservation ecology concerned with returning degraded ecosystems (as nearly as possible) to their natural state is
Using living organisms to clean up polluted ecosystems is known as
The Kissimmee River Project is an
attempt to restore the natural wetlands associated with the Kissimmee River
will require global, multinational cooperation