Biosphere practice

Which of the following statements about tropical forests is true? A) In tropical regions with distinct wet and dry seasons, tropical deciduous trees and shrubs are common. B) Tropical forests occur in equatorial regions with 6- to 8-hour days. C) The soils of tropical rain forests are typically rich in nutrients. D) Horizontal stratification provides many different habitats in tropical rain forests. E) Once stripped, tropical rain forests regrow quickly, although with slightly less diversity

A

While on a walk through a forest, you notice birds in trees, earthworms in the soil, and fungi on plant litter on the forest floor. Based on your observations, you conclude that each of these organisms occupies a different A) habitat. B) abiome. C) biosphere. D) biome. E) ecosystem.

A

The increase in global temperature resulting from the greenhouse effect is primarily due to A) CO2 allowing more solar radiation to penetrate to the Earthʹs surface. B) CO2 slowing the escape of heat from Earth. C) the loss of ozone that trapped cooling UV radiation in the atmosphere. D) CO2 slowing the escape of UV radiation from Earth. E) CFCs slowing the escape of heat from Earth.

B

The most complex and diverse biome is A) temperate forest B) tropical rain forest C) temperate grassland D) savanna E) chaparral

B

The number of species in a community is called the A) community. B) species richness. C) species diversity. D) species index. E) species population.

B

The primary decomposers of a community are called A) protozoa. B) detritivores. C) primary consumers. D) primary producers. E) herbivores.

B

When two different populations in a community benefit from their relationship with each other, the result is called A) partnership. B) mutualism. C) competition. D) herbivory. E) predation.

B

Which of the following has the greatest impact on the global water cycle? A) removing animals from their biome B) human destruction of forests C) human overuse of water resources for large cities D) connecting aquatic and terrestrial biomes E) cutting plants to prevent transpiration

B

Which of the following is a likely consequence of the thinning of the ozone layer? A) harm to the oceans B) increases in skin cancer C) increases in escape of heat from Earth D) global warming E) elimination of flying insects

B

Which of the following is an example of predation? A) mechanical devices, such as quills in a porcupine B) a hawk swooping down quickly to capture, kill, and eat a prairie king snake C) the vivid colors of the poison-arrow frog in Costa Rica D) a goldfinch feeding on the seeds of a thistle plant E) a lizardʹs camouflage

B

Which of the following statements about the phosphorus cycle is true? A) Phosphorus has its main abiotic reservoir in water. B) Phosphorus is cycled almost entirely within the soil, rather than transfered over long distance via the atmosphere C) Phosphorus cycling is not only local but also global D) Consumers obtain phosphorus in organic form from meats. E) Plants release dissolved phosphorus ions in the soil.

B

About one-third of all animal and plant species are concentrated on ________ of Earthʹs land. A) 5% B) 50% C) 1.5% D) 20% E) 10%

C

Denitrifying bacteria convert ________ to ________. A) nitrogen gas . . . ammonium B) nitrogen gas . . . nitrates C) nitrates . . . nitrogen gas D) ammonium . . . nitrogen gas E) nitrogen gas . . . nitrites

C

Except near hydrothermal vents, the communities of the oceanic aphotic zone get their energy mainly from A) oxidation of sulfur by sulfur bacteria. B) photosynthesis by local phytoplankton. C) organic matter sinking from the photic zone. D) photosynthesis by local zooplankton. E) oxidation of silicates by silicate bacteria.

C

Given that CO2 is produced by respiration, why does the amount of CO2 in the atmosphere remain relatively constant? (When answering this question, exclude the impact of human activities on atmospheric CO2.) A) CO2 is trapped in dead organismsʹ bodies. B) CO2 is split apart during photosynthesis. C) CO2 is converted in photosynthesis to carbohydrates. D) CO2 is a buffer. E) CO2 mostly forms carbonate rocks.

C

In many dense forests, plants living near the ground level engage in intense competition for A) water. B) carbon dioxide. C) sunlight. D) oxygen. E) nitrogen.

C

In which of the following biomes would you expect to find the highest abundance of large, grazing animals? A) temperate forest B) tropical rain forest C) temperate grassland D) chaparral E) desert

C

Most of the best agricultural soils in the United States are found in areas that were formerly A) tropical rain forest. B) savanna. C) temperate grasslands. D) taiga forest. E) tundra.

C

Most of the worldʹs deserts are located at latitudes where A) hot, dry air moving toward the equator rises. B) cold, dry air moving toward the equator descends. C) cold, dry air moving toward the poles descends. D) hot, dry air moving toward the poles rises. E) hot, dry air moving toward the poles descends.

C

Non-native species that are introduced in new environments, spread far beyond the original point of introduction, and cause damage are called A) enemy species. B) proprietary species. C) invasive species. D) predatory species. E) destructive species.

C

One reason it is important to understand community ecology is A) to provide a basis for farming protocols. B) to understand the life cycle of fish, such as cichlids. C) to aid in conservation of endangered species. D) to provide an enriched habitat for humans. E) for identification of stomach microbes.

C

Phytoplanktons are the major photosynthesizers in A) swamps. B) streams. C) the ocean photic zone. D) the intertidal zone. E) coral reefs.

C

Species found in only one place on Earth are called ________ species. A) hot spot B) exotic C) endemic D) native E) keystone

C

The bacteria that cause tooth decay have a ________ relationship with humans. A) commensalistic B) ammensalistic C) parasitic D) mutualistic E) competitive

C

The greatest annual input and least seasonal variation in solar radiation occurs in the A) Northern Hemisphere. B) Southern Hemisphere. C) tropics. D) polar regions. E) temperate zones.

C

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 A) genetic drift. B) evolution. C) secondary succession. D) a phylogenetic trend. E) a trophic chain.

C

When a crocodile eats a fish, the interspecific interaction between the two could be expressed as ________ for the crocodile and ________ for the fish. A) . . . + B) + . . . + C) + . . . D) . . . E) . . . ++

C

Which of the following environmental factors usually has the greatest direct effect on an organismʹs rate of water loss by evaporation? A) barometric pressure B) fires, hurricanes, and tornadoes C) wind D) moisture E) soil type

C

Which of the following factors is fundamentally responsible for the character of arctic tundra soils? A) high aluminum content due to a low rate of leaching B) abundant winter snow C) permafrost D) summer aridity E) secretion of acid by lichens and plant roots

C

Which of the following statements about zoned reserves is incorrect? A) An extensive region of land that includes one or more areas undisturbed by humans is called a zoned reserve. B) Costa Rica hopes to maintain at least 80% of its native species by using zoned reserves. C) The areas surrounding a zoned reserve are not to be used to support human populations. D) Ecosystems remain undisturbed by humans. E) Costa Rica is a world leader in establishing zoned reserves.

C

Which of the following statements regarding food webs is true? A) A consumer may eat only one type of producer. B) A hawk at the top of the food web is only a quaternary producer. C) Several species of primary consumers may feed on the same species of producer. D) Detritivores consume dead organic matter from a specific trophic level. E) Nutrient transfer moves from producer to consumer and back.

C

Which of the following tundra features would be found at the top of the Andes mountains in Ecuador? A) mostly sandy soil with a low pH B) areas of dry soil C) fierce winds and frigid nights D) a brief, bright growing season and a long, dark winter E) large, shallow-rooted vegetation

C

A series of reciprocal adaptations in two species defines A) competitive exclusion. B) niche compartmentalization. C) interspecific competition. D) coevolution. E) resource partitioning.

D

Currently, the single greatest threat to biodiversity is A) overpopulation. B) global warming. C) overexploitation of populations for food. D) habitat destruction due to humans. E) the introduction of exotic species.

D

Fragmented populations A) are composed of endemic species. B) are at little risk of extinction. C) are more vulnerable to the greenhouse effect than are populations that are not fragmented. D) are likely to exhibit low levels of genetic diversity. E) result from the introduction of endemic species.

D

Habitat fragmentation A) favors animals that prefer large, open ranges. B) favors parasites. C) results in a significant increase in diversity. D) often results from human activities. E) results from natural disasters.

D

In a food chain consisting of phytoplankton → zooplankton → fish → fishermen, the fishermen are A) primary producers. B) primary consumers. C) secondary consumers. D) tertiary consumers. E) secondary producers.

D

In an ecosystem, you would expect to find interspecific competition between A) two wasp species that mimic each otherʹs appearance. B) males of a species during the breeding season. C) males and females of a species in which both sexes occupy the same niche. D) populations of two species that occupy the same niche. E) a prey species and its predator.

D

In experimental studies conducted at the Hubbard Brook Experimental Forest, it was found that A) water runoff decreased in the deforested areas. B) water runoff stayed about the same in deforested areas. C) nitrogen loss was about double in deforested areas. D) water runoff increased in the deforested areas. E) most nutrients flowed into and then out of nondisturbed forests.

D

In terms of global air circulation, the tropical regions are the regions where air A) rises and warms, creating an arid belt. B) descends and warms, dropping rain. C) rises and cools, creating an arid belt. D) rises and cools, dropping rain. E) descends and warms, creating an arid belt.

D

Large coastal dead zones depleted of oxygen are primarily caused by A) acid precipitation. B) DDT released into the environment. C) PCBs released into the environment. D) nutrient pollution. E) CFCs released into the environment.

D

On Earth, most organic molecules are produced by A) glycolysis. B) photorespiration. C) cellular respiration. D) photosynthesis. E) hydrolysis.

D

One mechanism that prey populations evolve to avoid predation is A) increasing the number of offspring produced. B) secretion of enzymes that break down toxic plant compounds. C) secretion of digestive enzymes that hydrolyze glucose. D) camouflage. E) development of a short gestation period.

D

The flow of ________ into ecosystems occurs in one direction only, while ________ are recycled within the ecosystem itself. A) organic compounds . . . minerals B) minerals . . . energy compounds C) food . . . energy D) energy . . . chemicals E) genetic information . . . genotypes

D

We expect that a keystone species that is a predator will A) reduce the diversity of the community. B) harvest prey species down to extinction. C) help many of its prey reproduce. D) maintain the species diversity in a community. E) be a parasite.

D

Which of the following substances is cycled between organic matter and abiotic reservoirs? A) protein B) nucleic acid C) enzymes D) carbon E) fat

D

Which of the following options correctly pairs a biome and its characteristics? A) temperate grassland=cool to cold winters, wet summers B) desert= dry, hot, no rainfall at all C) chaparral=mild, rainy winters; long, hot, but wet summers D) savanna=long, cold winters, vegetation dominated by conifers E) tundra=very cold winters; only the upper layer of the soil thaws during summer

E

Which of the following statements about biomes, the major terrestrial ecosystems covering the Earth, is true? A) The different types of biomes are distinguished by wind and sunlight. B) Each of the eight major biomes is restricted to just one or two continents. C) Most biomes are characterized by a particular group of species. D) Most natural biomes are unaffected by human activity. E) The major factors affecting the distribution of biomes are temperature and rainfall.

E

Which of the following statements about movement corridors is true? A) Movement corridors are detrimental to species that migrate between habitats seasonally. B) Movement corridors can prevent the spread of disease. C) Movement corridors can promote inbreeding in declining populations. D) Movement corridors are most important to humans. E) Movement corridors can connect otherwise isolated habitat patches.

E

Which of the following statements about the nitrogen cycle is true? A) Nitrogen cannot be cycled through living organisms. B) When plants and animals die, nitrogen is removed from the nitrogen cycle. C) Nitrogen gas is converted to nitrates in plant leaves. D) Nitrogen is a component of all fats. E) The nitrogen cycle requires different types of bacteria.

E

Which of the following represents a step in the nitrogen cycle? A) nitrogen-fixing bacteria convert atmospheric nitrogen to ammonia B) atmospheric nitrogen converted to nitrates C) nitrites binding to soil particles D) ammonium converted to atmospheric nitrogen E) conversion of nitrates to atmospheric nitrogen in the presence of oxygen

A

Which of the following statements about protected areas is incorrect? A) We now protect 25% of the land areas of the planet. B) National Parks are the only one type of protected areas. C) Most reserves are smaller in size that the ranges needed by some of the species they are meant to protect. D) Management of the protected areas must coordinate with the management of lands outside the protected zone. E) Biodiversity hot spots are important areas to protect.

A

A whale in the middle of the Atlantic Ocean is in which oceanic zone? A) pelagic B) intertidal C) estuarine D) benthic E) neritic

A

Approximately ________ living species have been named and described. A) 1.8 million B) 750,000 C) 80 million D) 30 million E) 10 million

A

Approximately ________ of the prescriptions dispensed by U.S. pharmacies contain substances derived from plants. A) 25% B) 50% C) 10% D) 75% E) 30%

A

Changes in the seasons are caused by A) the tilt of Earthʹs axis toward or away from the sun B) annual cycles of temperature and rainfall C) variation inthe distance between Earth and the sun D) anu annual cycle in the sunʹs energy output E) the periodic build up of heat energy at the equator

A

Chaparral vegetation occurs around much of the central valley of central and southern California. This biome is very similar to that found A) in the Mediterranean region. B) in the Australian interior. C) along the coast of Great Britain. D) in central Asia. E) on the southeast coast of the United States.

A

Coniferous forests are dominated by A) spruce, pine, fir B) oak, maple C) hickory, birch D) Joshua tree E) shrubs

A

Dinoflagellates are important to coral and coral-dwelling animals because they A) produce energy that is used by coral animals through photosynthesis. B) produce CO2 and nitrogen for coral. C) maintain environmental conditions throughout the coral system. D) provide shelter for the fast-growing seaweeds associated with coral. E) are toxic to species that prey on reef-dwelling fish.

A

Global warming is the result of A) rising concentration of greenhouse gases. B) pollution. C) species extinction. D) rises in ocean levels. E) increasing occurrence of heat waves.

A

In a hypothetical food chain consisting of grass, grasshoppers, sparrows, and hawks, the grasshoppers are A) primary consumers. B) primary producers. C) secondary consumers. D) detritivores. E) secondary producers.

A

Rachel Carsonʹs book, Silent Spring, deals with the A) environmental effects of pesticides. B) hydrological cycle. C) destruction of polar habitats caused by global warming. D) fate of tropical rain forests. E) effects of lynx predation on snow hare populations.

A

The current rate of extinction may be as much as ________ times higher than at any other time in the past 100,000 years. A) 1,000 B) 10 C) 100 D) 5,000,000 E) 10,000

A

The immediate results of the widespread use of pesticides and fertilizers included ________, but long-term results included ________. A) dramatic increases in crop yields . . . the evolution of pest resistance B) dramatic declines in crop pests . . . localized distribution of DDT C) terrible declines in agricultural productivity . . . worldwide distribution of DDT D) global declines in undesirable pests, such as mice, rats, crows, and sharks . . . increases in these pests E) the increased spread of malaria . . . delayed resistance to pesticides

A

The kind of vegetation in a tropical rain forest is generally determined by the amount of A) rainfall. B) carbon dioxide in the air. C) nitrogen in the soil. D) light. E) minerals in the soil.

A

The level of ecologic organization that incorporates abiotic factors is the A) ecosystem. B) symbioses C) species. D) population. E) community

A

The three greatest current threats to biodiversity, in order starting with the greatest, are A) habitat destruction, the introduction of invasive species, and overexploitation. B) the introduction of invasive species, overexploitation, and habitat destruction. C) the introduction of invasive species, habitat destruction, and overexploitation. D) overexploitation, habitat destruction, and the introduction of invasive species. E) habitat destruction, overexploitation, and the introduction of invasive species.

A

The greatest challenge facing the zoned reserve systems of Costa Rica is A) poaching and illegal mining. B) the growing human population. C) forest fires. D) high predation by jaguars. E) soil erosion.

B

An economist monitoring the number of wolves in a wild life refuge over a 5-year period id studying ecology at which level? A) organism B) population C) community D) ecosystem E) biosphere

B

An organismʹs responses to climate change that result in phenotypic variation is called A) alteration of generation. B) phenotypic plasticity. C) mutation. D) genetic drift. E) population fragmentation.

B

An owl and a hawk both eat mice. Which of these terms describes the relationship between a hawk and an owl? A) parasitism B) competition C) predation D) mutualism E) commensalism

B

Average global temperature has risen ________ over the past 100 years. A) 10°F B) 0.8°C C) 1°F D) 10°C E) 100°F

B

Biodiversity considers A) the fate of water in the ecosystem. B) the genetic diversity within and between populations of a species. C) mutualistic associations between fungi and algae. D) commensal relationships between species. E) the relationships of individuals to a food chain.

B

Biological control is defined as A) the use of chemicals, such as pesticides, to control pests. B) the intentional release of a natural enemy of a pest population. C) an intentional attempt to increase the numbers of specific prey populations. D) the exploitation of coevolutionary principles to produce pesticides. E) a mechanism for encouraging growth of an invasive plant or animal.

B

CO2 flooding into the atmosphere is absorbed by ________ and converted into biomass. A) other atmosphere gases B) photosynthetic organisms C) the sun D) large land masses E) the ozone layer

B

Carbon mainly cycles between the biotic and abiotic worlds through the processes of A) transpiration and photosynthesis. B) respiration and photosynthesis. C) evaporation and photosynthesis. D) respiration and transpiration. E) respiration and evaporation.

B

Fresh water and seawater mix in a(n) A) limnetic zone. B) estuary. C) littoral zone. D) pelagic zone. E) benthic zone.

B

In addition to environmental factors, community composition of plants can be severely compromised by A) lack of soil nitrogen. B) parasites and pathogens. C) introduction of chestnut trees. D) rapid coevolution. E) non-native birds.

B

In the 2,000 years that humans have lived on Madagascar, the island has lost approximately ________ of its native species. A) 30% B) 50% C) 25% D) 10% E) 75%

B

Movement corridors are A) the routes taken by migratory animals. B) Strips or clumps of habitat that connect isolated fragments of habitat. C) landscapes that include several ecosystems. D) edges or bounderies between ecosystems E) buffer zones that promote the long-term viability of protected areas

B

Some populations may avoid extinction as the climate changes, especially those with high genetic variability and short life spans, through A) genetic modification. B) evolutionary adaptation. C) genetic shift. D) feedback inhibition. E) distribution of populations.

B

Why is the runoff from fertilized agricultural fields, even if free of pesticides, often harmful to the ecosystems of temperate lakes? A) Fertilizer compounds are toxic to fish. B) The runoff causes a surface algal bloom, which reduces the lakeʹs oxygen by cutting off the sunlight and fouling the water with dead organic matter. C) Runoff water pools at the lakeʹs bottom, where the fertilizer compounds react with materials in the sediment to form toxic substances. D) The runoff is acid, and acidification kills key lake organisms. E) The runoff raises the levels of inorganic nutrients in the surface waters to levels that are toxic for algae and other lake organisms.

B

Within an ecosystem, a tree is a A) tertiary consumer. B) producer. C) secondary consumer. D) primary consumer. E) detritivore.

B

A community is composed of A) the factors that constitute an organismʹs niche. B) several ecosystems on one continent. C) one species of organism living in a specific environment on Earth. D) living organisms and their nonliving environment. E) potentially interacting populations of different kinds of organisms.

E

Chlorofluorocarbons (CFCs) A) were once used as an energy source. B) contribute to acid precipitation. C) were once used as pesticides. D) accumulate in the tissues of organisms. E) deplete the ozone layer.

E

Eutrophication of a lake could occur if A) sewage was treated before being dumped into the lake. B) runoff from overfertilized lawns was prevented from reaching the lake. C) fish were removed. D) fertilizers were applied in an insoluble form. E) phosphate-rich detergents were dumped into the lake.

E

In an ecosystem, about how much of the energy in producers will be available to secondary consumers in this ecosystem? A) 100% B) about 0.1% C) 50% D) about 10% E) about 1%

E

Species in widely separated biomes often appear display similar characteristics because of A) mutations. B) dominance. C) coevolution. D) evolutionary drift. E) convergence.

E

The Yukon to Yellowstone Initiative is a plan to A) connect all of the national parks in the western United States. B) connect all of the national parks in the United States to the provincial parks in Canada. C) connect all of the national parks in the United States. D) create a giant, fenced, private land area between the national parks in the United States to create a protected zone for wildlife. E) connect parks in the United States and Canada with protected corridors where wildlife can travel safely.

E

The adaptations of pronghorns A) to the open plains and shrub deserts of North America have helped them spread to nearly every continent. B) demonstrate that meeting the demands of local environmental conditions helps organisms extend their ranges to other types of environments. C) allow them to survive in forests, since they are herbivores. D) include a reflective coat, an ability to find small pools of water, and chemical defenses against most predators. E) to abiotic and biotic factors by natural selection are highly successful in open country

E

The dominant herbivores in savannas are A) worms. B) gophers. C) antelope. D) giraffes. E) insects.

E

The increase in the concentration of a substance in the tissues of organisms as it is passed up a food chain is called A) maximization. B) incrementalization. C) predatory accumulation. D) concentration of toxins. E) biological magnification.

E

The major reason for tropical deforestation is A) hurricane destruction of large regions. B) governments clearing forests to build cities. C) governments of developing countries selling off land to earn cash. D) natural succession as global warming occurs. E) people clearing forests to open up land for agriculture.

E

The primary goal of conservation biology is to A) integrate human culture back into nature. B) maximize the land set aside for wildlife. C) catalogue species. D) estimate the total number of species that exist. E) counter the loss of biodiversity.

E

The primary source of energy for hydrothermal vent communities is A) reduction of sulfates in the vent water. B) reduction of carbon dioxide in the vent water. C) oxidation of petroleum compounds in the vent water. D) the heat of the water emerging from the vents. E) oxidation of hydrogen sulfide in the vent water.

E

The reason that the pronghorn antelope is not found outside North America is most likely that A) there are too many pronghorn predators outside North America. B) its temperature requirements are stringent and not met outside North America. C) it is a relatively new species in evolutionary terms. D) its nutritional requirements cannot be met outside this region. E) it has never dispersed beyond this region.

E

The sum of all Earthʹs ecosystems is called the A) troposphere. B) stratosphere. C) lithosphere. D) hydrosphere. E) biosphere.

E

The sum total of a populationʹs use of the biotic and abiotic resources of its habitat constitutes its A) environment. B) distribution. C) range. D) evolution. E) niche.

E

The top predators are most severely affected by pesticides such as DDT or manufacturing toxic substances such as PCBs, because they A) are especially sensitive to chemicals. B) have rapid reproductive rates. C) have very long life spans. D) stores the pesticides or toxic substances in their tissues. E) Consume prey in which pesticides or toxic substances are concentrated.

E

Which of the following biomes is dominated by coniferous trees adapted to surviving long, harsh winters and short, wet summers? A) chaparral B) savanna C) tundra D) temperate broadleaf forest E) coniferous forests

E