Chapter 52-54 Mastering
The symbols +, -, and 0 are to be used to show the results of interactions between individuals and groups of individuals. The symbol + denotes a positive interaction, - denotes a negative interaction, and 0 denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. What interactions exist between cellulose-digesting organisms in the gut of a termite and the termite?
+/+
The symbols +, -, and 0 are used to show the results of interactions between individuals and groups of individuals. The symbol + denotes a positive interaction, - denotes a negative interaction, and 0 denotes interactions in which individuals are not affected. The first symbol refers to the first organism mentioned. What interactions exist between a lion pride and African wild dogs, if the dogs are found to typically avoid areas with lions?
+/-
Aquatic biomes can be distinguished by chemical characteristics such as dissolved oxygen content and salinity and by physical characteristics such as water flow
-Estuaries are very productive and are used as breeding grounds by many species of fish. -Temperature drives water movement in some lakes. -Wetlands have slow water movement or no water movement and no turnover. -A freshwater organism permanently attached to the substrate would be unlikely to survive and reproduce in an estuary. -Tropical coral reefs generally exist in relatively shallow areas of the ocean.
Approximately how many kilograms (kg) of carnivore (secondary consumer) biomass can be supported by a field plot containing 1000 kg of plant material?
10
Assume there are 200 MendAliens living on an island in my back yard. If my island has an area of 20 hectares, what is the population density of MendAliens in terms of MendAliens per hectare?
10 MendAliens per hectare
You are doing a mark-recapture experiment to determine the population size of the MendAliens living on an island in my back yard. Initially, you catch and mark 130 MendAliens, which you then release. Next, you capture 90 MendAliens, of which 20 are marked. What is your estimate of the population size of MendAliens living on the island in my back yard?
585
The symbols +, -, and 0 are used to show the results of interactions between individuals and groups of individuals. The symbol + denotes a positive interaction, - denotes a negative interaction, and 0 denotes interactions in which individuals are not affected. The first symbol refers to the first organism mentioned. Which fact is correct when describing species interactions?
A +/- interaction could shift to +/0 or +/+ over time, depending on other factors such as competition, population density, or environmental changes.
In the figure, which of the arrows represents the carrying capacity?
Arrow C
Which of the following statements are true of logistic growth?
As the population approaches carrying capacity, it grows more slowly. When the population reaches carrying capacity, it stops growing.
Which of the following statements about human populations in industrialized countries is incorrect?
Birth rates and death rates are high
Which processes increase a population's size?
Births and immigration
Which of the following is an example of a commensalism? Which of the following is an example of a commensalism?
Cattle egrets eating insects stirred up by grazing bison
What are population dynamics?
Changes in populations through time.
Which of the following statements about density-independent growth is true?
Density-independent growth is also known as exponential growth.
Which of the following statements is consistent with the principle of competitive exclusion?
Even a slight reproductive advantage will eventually lead to the elimination of the less well adapted of two competing species.
Which factor does not affect a habitat's carrying capacity?
Genetic variation in the population
Scientists grew a population of yeast cells in a flask to which they provided a constant supply of nutrients. As the population of yeast cells increased, competition for the nutrients also increased. This caused the population to grow more slowly, until the rate at which the yeast cells used the nutrients was equal to rate at which the nutrients were supplied to the flask. Which of the three graphs shown in Part G best represents the growth of these yeast population?
Graph A
A pair of coyotes colonized a large island where rodents (their prey) were abundant. At first the number of coyotes increased. But as the coyote population increased, competition for prey also increased and the coyote population grew more slowly. In some years, weather conditions killed many of the rodents, causing some coyotes to starve. In other years, weather conditions were favorable for the rodent poulation, allowing the coyotes to thrive, reproduce, and raise many pups. Which of the three graphs shown in Part G best represents the growth of this coyote population?
Graph B
A female darkling beetle laid her eggs in a sack of corn meal. The corn meal was an excellent source of food for the beetle larvae (mealworms), and the beetle population quickly increased. After four months, the beetles had eaten all of the corn meal, and the adult beetles flew away to find new food sources.
Graph C
Why do moderate levels of disturbance result in an increase in community diversity?
Habitats are opened up for less competitive species
In terms of community ecology, why are pathogens often more virulent now than in the past?
Human activities are transporting pathogens into new habitats (or communities) at an unprecedented rate
Which of the following statements about a population experiencing logistic growth is true?
If N is greater than K, the population will shrink.
Why does the U.S. population continue to grow even though the United States has essentially established a zero population growth (ZPG)?
Immigration
Which of the following statements regarding turnover in a lake is correct?
In fall turnover, dense water at 4°C sinks and disturbs sediments in the benthic zone.
Which of the following statements is a likely explanation for why invasive species take over communities into which they have been introduced?
Invasive species are not held in check by the predators and agents of disease that have always been in place for native species.
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.
Which statement accurately describes Earth on February 21, a date that falls between the December solstice and the March equinox?
Locations in the Southern Hemisphere experience more than 12 hours of daylight.
Which of the following statements best describes the interaction between fire and ecosystems?
Many kinds of plants and plant communities have adapted to frequent fires
Which of the following traits is characteristic of K-selected populations?
Offspring with good chances of survival
Which of the following measurements would be most helpful in understanding the structure of an ecological community? I) determining how many species are present overall II) determining which particular species are present III) determining the kinds of interactions that occur among individuals of the same species IV) determining the abundance of resources available for one species
Only I and II
Based on the food web diagram, label the following statements as true or false. Drag "True" or "False" to the end of each statement. ResetHelp
Phytoplankton are primary consumers. False Squids are secondary consumers. True Squids are tertiary consumers. True Leopard seals are quaternary consumers. True
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.
For mountain ranges that are subjected to prevailing winds, why is the climate drier on the leeward (downwind) side?
Pushed by the prevailing winds on the windward side, air is forced to rise, cool, condense, and drop its precipitation, leaving drier air to descend the leeward side.
Which of the following is a correct statement about MacArthur and Wilson's island equilibrium model?
Small islands receive few new immigrant species.
Which of the following statements is supported by the trophic relationships shown in the diagram?
Squids eat fishes
Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species?
Temperate broadleaf forest
Which statement regarding the June solstice is true?
The Northern Hemisphere is tilted toward the sun.
A fish swimming into an estuary from a river would have which of the following as its greatest physiological challenge?
The change in water solute content would challenge the osmotic balance of the fish.
At what time of year is the intensity of solar radiation striking each of Earth's hemispheres weakest?
The intensity of solar radiation is weakest in the Southern Hemisphere in June and in the Northern Hemisphere in December.
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.
As N approaches K for a certain population, which of the following outcomes is predicted by the logistic equation?
The population growth rate will approach zero.
Which of these is characteristic of the photic zone of a freshwater biome?
The presence of algae
Which of the following statements are true of a population at carrying capacity?
The rate at which resources are used is equal to the rate at which they are supplied. The population growth rate equals zero. The birth rate equals the death rate.
Suppose that humans increase their consumption of Antarctic fishes, causing a significant reduction in the size of fish populations. What would be the most likely effect of a reduction in the size of Antarctic fish populations? Drag the terms on the left to the appropriate blanks in the sentences on the right. Terms may be used once, more than once, or not at all.
The sperm whale population would decrease. The elephant seal population would decrease. The carnivorous plankton population would increase.
Which of the following is a widely supported explanation for the tendency of tropical communities to have greater species diversity than temperate or polar communities?
Tropical communities have higher sunlight and precipitation, and are generally older than temperate or polar communities.
True or false? Factors that determine the per capita rate of increase of a population include the age of breeding and the number of offspring produced each year.
True
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 population reached the carrying capacity of that environment.
True
Under which of the following conditions would a population most likely experience exponential growth?
Young populations with few individuals.
There are more species in tropical areas than in places more distant from the equator. This is probably a result of ________.
a longer time frame without disturbances for evolution and speciation
Which of the following is an example of Batesian mimicry?
a nonvenomous larva of a moth that moves like a venomous snake
Oyster populations are primarily, if not exclusively, composed of _____.
adults
The longest food chain in this food web includes nine groups of organisms. Which of the following groups is included in that food chain?
birds
Which of the following factors does not contribute to environmental resistance?
birth rate
An egret eats insects stirred up by grazing animals. Which of these terms applies to the relationship between the egret and the grazing animal?
commensalism
According to the nonequilibrium model of community diversity, ________.
communities are constantly changing after being influenced by disturbances
Humans and sharks both eat fish. Which of these terms applies to the relationship between the human and the shark?
competition
Which of the following causes populations to shift most quickly from an exponential to a logistic population growth?
competition for resources
Generally speaking, deserts are located in places where air masses are usually ________.
descending
An earthworm that feeds on the remains of plants and animals is acting as a _____.
detritivore
Which of these organisms has a survivorship curve similar to that of humans?
elephants
A(n) _____ is a region where fresh water and salt water mix.
estuary
Which of these organisms has a survivorship curve similar to that of oysters?
grasses
During exponential growth, a population always
has a constant per capita population growth rate
When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes _____.
in biomes at different latitudes
As a population approaches carrying capacity, environmental resistance __________.
increases
Zoonotic disease _____.
is caused by pathogens that are transferred from other animals to humans by direct contact or by means of a vector
Which pair of terms most accurately describes life history traits for a stable population of wolves?
iteroparous; K-selected
In deep water, which of the following abiotic factors would most limit primary productivity?
light availability
What does the orange graph line represent?
logistic growth
The _____ biome is the largest of Earth's biomes.
marine
A population's carrying capacity
may change as environmental conditions change
Food chains are sometimes short because _____.
most of the energy in a trophic level is lost as it passes to the next higher level
Humans who have pets tend to be healthier than humans who do not have pets. Which of these terms applies to the relationship between a human and a pet?
mutualism
Which statements about K are correct? I) K varies among populations. II) K varies in space. III) K varies in time. IV) K is constant for any given species.
only I, II, and III
Which of these terms applies to the relationship between a dog and a blood-sucking tick?
parasitism
A human eats a deer. Which of these terms applies to the relationship between the human and the deer?
predation
Keystone predators can maintain species diversity in a community if they _____.
prey on the community's dominant species
A cow eating grass is an example of a _____.
primary consumer
In an ecosystem, phytoplankton are _____.
producers
The oceans affect the biosphere in all of the following ways except
regulating the pH of freshwater biomes and terrestrial groundwater.
What does the right y-axis represent?
resources, with quantity decreasing from bottom to top
Which of these species typically has a mortality rate that remains fairly constant over an individual's life span?
robins
When a human eats a steak, the human is acting as a
secondary consumer
Which trophic levels do fishes occupy in this food web?
secondary consumers tertiary consumers quaternary consumers
The mark-recapture method would be best for sampling a population of _____.
sharks
According to the island equilibrium model, species richness would be lowest on an island that is ________.
small and remote
Which of the following groups can be quaternary consumers in this food web?
sperm whales
The benthic zone of aquatic environments is defined as the _____.
substrate at the bottom of the body of water
In mountainous areas of western North America, north-facing slopes would be expected to _____.
support biological communities similar to those found at higher elevations on similar south-facing slopes
A human who just ate a hamburger is eaten by a shark while swimming. The shark is acting as a _____.
tertiary consumer
In the region of the Rocky Mountains, imagine that one local variety of Ponderosa pine (Pinus ponderosa) predominantly occurs between 5,000-8,500 feet in elevation, where it can best tolerate temperatures and precipitation. If future climate change in this region causes the temperature to increase and rainfall to decrease, then which of the following changes might an ecologist predict about the variety's range?
that variety will occur at higher elevations and/or higher latitudes
Which of the following is an example of aposematic coloration?
the brightly colored patterns of monarch butterfly caterpillars
Which of the following causes seasons on Earth?
the constant tilt of the Earth, combined with its orbit around the sun
A recent study of ecological footprints concluded that _____.
the ecological footprint of the United States is large because per capita resource use is high
Analyzing ecological footprints reveals that
the ecological footprint of the United States is large because per capita resource use is high.
Five different baleen whale species are endangered and may go extinct. What would be the most likely effect of removing all baleen whales from this food web?
the krill population would increase
One plausible hypothesis to explain why species richness is higher in tropical than in temperate regions is that ________.
tropical regions generally have more available water and higher levels of solar radiation
Which of the following is an example of Müllerian mimicry?
two species of unpalatable butterfly that have the same color pattern
Which of the following is an important feature of most terrestrial biomes?
vegetation demonstrating vertical layering
Which aquatic biome listed here is one of the most productive on Earth, and why?
wetlands, nutrient rich high-moisture soils
