A human eats a deer. Which of these terms applies to the relationship between the human and the deer?
Humans and sharks both eat fish. Which of these terms applies to the relationship between the human and the shark?
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?
Which of these terms applies to the relationship between a dog and a blood-sucking tick?
An egret eats insects stirred up by grazing animals. Which of these terms applies to the relationship between the egret and the grazing animal?
Which of the following is the most logical conclusion about the distribution of the two species of barnacle, Chthamalus and Balanus?
Balanus is less able to resist desiccation than Chthamalus.
As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. When you bring them into the laboratory, their offspring behave in the same manner. You have discovered an example of
Which of the following is an example of cryptic coloration?
a "walking stick" insect that resembles a twig
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 example of Batesian mimicry?
a non-venomous snake that looks like a venomous snake
Which of the following is an example of aposematic coloration?
stripes of a skunk
Dwarf mistletoes are flowering plants that grow on certain forest trees. They obtain nutrients and water from the vascular tissues of the trees. The trees derive no known benefits from the dwarf mistletoes. Which of the following best describes the interactions between dwarf mistletoes and trees?
Evidence shows that some grasses benefit from being grazed. Which of the following terms would best describe this plant-herbivore interaction?
Which of the following types of species interaction is correctly paired with its effects on the density of the two interacting populations?
commensalism: as one increases the other stays the same
Which of the following examples best describes an ecological community?
The interactions of all the plant and animal species inhabiting a 2 hectare forest.
Community ecologists would consider which of the following to be most significant in understanding the structure of an ecological community?
the relative abundance of species, determining how many species are present overall, which particular species are present, the kinds of interactions that occur among organisms of different species
Which of the following studies would a community ecologist undertake to learn about competitive interactions?
the grass species preferred by grazing pronghorn antelope and bison, selectivity of nest sites among cavity nesting songbirds, nitrate and phosphate uptake by various species of hardwood forest tree species, stomach analysis of brown trout and brook trout in streams where they coexist
All of the following have been used by plants to avoid being eaten except
producing tissues that have unappealing colors.
Which of the following describes the relationship between legumes and nitrogen-fixing bacteria?
The species richness of a community refers to the
number of different species.
The dominant species in a community is
the species that contributes the most biomass to the community.
In an ecosystem, phytoplankton are
An earthworm that feeds on the remains of plants and animals is acting as a
When a human eats a steak, the human is acting as a
A cow eating grass is an example of a
A human who just ate a hamburger is eaten by a shark while swimming. The shark is acting as a
In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely a(n)
Elephants are not the most common species in African grasslands. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following describes why elephants are the keystone species in this scenario?
Essentially all of the other species depend on the presence of the elephants to maintain the community.
Which of the following members of a marine food chain occupies a similar tropic level to a grasshopper in a terrestrial food chain?
Approximately how many kg of carnivore production can be supported by a field plot containing 2000 kg of plant material?
You are most likely to observe primary succession in a terrestrial community when you visit a(n)
recently created volcanic island.
is caused by pathogens that are transferred from other animals to humans by direct contact or by means of a vector.
How are matter and energy used in ecosystems?
Matter is cycled through ecosystems; energy is not.
A cow's herbivorous diet indicates that it is a(n)
Which of the following are responsible for the conversion of most organic material into CO2, which can be utilized in primary production?
What is the most important role of photosynthetic organisms in an ecosystem?
converting inorganic compounds into organic compounds
Which of the following is an example of an ecosystem?
Interactions between all of the organisms and their physical environment in a tropical rain forest.
Which of the following is true of detrivores?
They convert organic materials from all trophic levels to inorganic compounds usable by primary producers.
Subtraction of which of the following will convert gross primary productivity into net primary productivity?
the energy used by autotrophs in respiration
A porcupine eats 3,000 J of plant material. 1,600 J is indigestible and is eliminated as feces. 1,300 J are used in cellular respiration. What is the approximate production efficiency of this animal?
Which animal product is least efficient at converting feed consumed into the final product?
Roughly how many kilograms of pork do you expect to get for every 100 kilograms of feed consumed?
Assume you are raising beef and that feed is costing you $1.00 per kilogram. Roughly how much money are you spending on feed for each kilogram of beef produced?
Surprisingly, milk has a conversion efficiency greater than 100%. What is the best explanation for this?
Most of milk's mass comes from water consumption, not feed consumption.
For a country with abundant land and water resources but limited financial resources, which animal product would most likely be favored by agricultural policy?
For a country where chicken raising and eating is a cultural taboo but water resources are scarce, which animal product would most likely be favored by agricultural policy?
Despite its high resource usage, beef is a major commodity due to the high value per kilogram of the final product. Which of the following changes would cause a reduction in beef production?
a dramatic rise in the cost of feed, land, and water to the beef producer, an agricultural program that subsidized pork production so that the profit per kilogram of pork was comparable to that for beef, a recipitous fall in the price per kilogram of beef
How does inefficient transfer of energy among trophic levels result in the typically high endangerment status of many top predators?
Top-level predators are destined to have small populations that are sparsely distributed.
In general, the total biomass in a terrestrial ecosystem will be greatest for which trophic level?
For most terrestrial ecosystems, pyramids of numbers, biomass, and energy are essentially the same-they have a broad base and a narrow top. The primary reason for this pattern is that
at each step, energy is lost from the system as a result of keeping the organisms alive.
Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems?
Energy transfer between tropic levels is in almost all cases less than 20% efficient.
Which statement best describes what ultimately happens to the chemical energy that is not converted to new biomass in the process of energy transfer between trophic levels in an ecosystem?
It is dissipated into space as heat in accordance with the second law of thermodynamics.
Which of the following statements about the movement of nutrients through an ecosystem is true?
Carbon cycles between the atmosphere and living biomass.
True or false? Local biogeochemical cycles are isolated within their particular ecosystem and all ions and molecules remain in that ecosystem permanently.
Which area is not one of the three major reservoirs of the global carbon cycle?
True or false? In the global carbon cycle, rivers link the terrestrial and marine reservoirs of carbon, whereas carbon exchange between the atmosphere and the ocean is achieved by active transport.
How does carbon move from the biota to the atmosphere?
Carbon dioxide is released during cellular respiration.
How have humans altered the global carbon cycle?
Carbon inputs into the atmosphere have risen.
How do greenhouse gases contribute to global warming?
They prevent infrared light from leaving Earth's atmosphere.
The high levels of pesticides found in birds of prey is an example of
When levels of CO2 are experimentally increased, C3 plants generally respond with a greater increase in productivity than C4 plants. This is because
C3 plants are more limited than C4 plants by CO2 availability because of transpirational water loss.
Which of the following describes carbon dioxide, methane, and water vapor re-reflecting infrared radiation back toward Earth?
Which of the following causes excessively high levels of toxic chemicals in fish-eating birds?
Agricultural lands frequently require nutritional supplementation because
the nutrients that enter the plants are not returned to the soil on lands where they are harvested.
Which of the following statements best describes why biologists are currently concerned with global warming and the thawing of permafrost in many areas of the tundra biome?
The bacterial decomposition of the thawed organic materials on the widespread areas of the tundra will produce large quantities of CO2, which will add to greenhouse gases and exacerbate global warming.
The most likely cause for the shift in caterpillar peak mass is
Why are ecologists concerned about the shift in date from May 28 in 1980 to May 15 in 2000 of the caterpillar peak mass?
The flycatcher nestlings in 2000 will miss the peak mass of caterpillars and may not be as well fed.