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biology final, question block with chapters 34, 37, 38

the sum of all the Earth's ecosystems is called the


the primary source of energy for hydrothermal vent communities is

oxidation of hydrogen sulfide in the vent water

while on a walk through a forest, you notice birds in the 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


Rachel Carson's book , Silent Spring, deals with the

environmental effects of pesticides

the level of ecologic organization that incorporates abiotic factors is the


the immediate results of the widespread use of pesticides and fertilizers included ______, but long-term results included ______.

dramatic increases in crop yields, the evolution of pest resistance

in many dense forests, plants living near the ground level engage in intense competition for


which of the following environmental factors usually has the greatest direct effect on an organism's rate of water loss by evaporation?


the reason that the pronghorn antelope is not found outside North America is most likely that

it has never dispersed beyond this region

the adaptations of pronghorns

to abiotic and biotic factors by natural selection are highly successful in open country

changes in the seasons are caused by

the tilt of Earth's axis toward or away from the sun

in terms of global air circulation, the tropical regions are the regions where air

rises and cools, dropping rain

the greatest annual input and least seasonal variation in solar radiation occurs in the


most of the world's deserts are located at latitudes where

cold, dry air moving toward the poles descends

a whale in the middle of the Atlantic Ocean is in which oceanic zone?


except near hydrothermal vents, the communities of the oceanic aphotic zone get their energy mainly from

organic matter sinking from the photic zone

phytoplanktons ar the major photosynthesizers in

the ocean photic zone

an economist monitoring the number of wolves in a wild refuge over a 5-year period is studying ecology at which level?


freshwater and seawater mix in a(n)


why is the runoff from fertilized agricultural fields,even if free of pesticides, often harmful to the ecosystems of temperate lakes?

the runoff causes a surface algal bloom, which reduces the lake's oxygen by cutting off the sunlight and fouling the water with dead organic matter

species in widely separated biomes often appear display similar characteristics because of


which of the following statements about biomes, the major terrestrial ecosystems covering the Earth, is true?

the major factors affecting the distribution of biomes are temperature and rainfall

which of the following statements about tropical forests is true?

in tropical regions with distinct wet and dry seasons, tropical deciduous trees and shrubs are common

the kind of vegetation in a tropical rain forest is generally determined by the amount of


the major reason for tropical deforestation is

people clearing forests to open up land for agriculture

the dominant herbivores in savannas are


which of the following options correctly pairs a biome and its characteristics?

tundra=very cold winters; only the upper layer of soil thaws during the summer

chaparral vegetation occurs around much of the central valley of central and southern California. this biome is very similar to that found

in the Mediterranean region

most of the best agricultural soils in the United States are found in areas that were formerly

temperate grasslands

in which of the following biomes would you expect to find the highest abundance of large, grazing animals?

temperate grasslands

which of the following biomes is dominated by coniferous trees adapted to surviving long, harsh winters and short, wet summers?

coniferous forests

coniferous forests are dominated by

spruce, pine, fir

the most complex and diverse biome is

tropical rain forest

which of the following tundra features would be found at the top of the Andes mountains in Ecuador?

fierce winds and frigid nights

which of the following factors is fundamentally responsible for the character of arctic tundra soils?


which of the following has the greatest impact on the global water cycle?

human destruction of forests

a community is composed of

potentially interacting populations of different kinds of organisms

one reason it is important to understand community ecology is

to aid in conservation of endangered species

when a crocodile eats a fish, the interspecific interaction between the two could be expressed as ______ for the crocodile and ______ for the fish.

+, -

an owl and a hawk both eat mice. which of these terms 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


which of the following is an example of predation?

a hawk swooping down quickly to capture, kill, and eat a prairie king snake

in an ecosystem, you would expect to find interspecific competition between

populations of two species that occupy the same niche

dinoflagellates are important to coral and coral-dwelling animals because they

produce energy that is used by coral animals through photosynthesis

one mechanism that prey populations evolve to avoid predation is


the bacteria that cause tooth decay have a ______ relationship with humans.


in addition to environmental factors, community composition of plants can be severely compromised by

parasites and pathogens

on Earth, most organic molecules are produced by


which of the following statements regarding food webs is true?

several species of primary consumers may feed on the same species of producer.

we expect that a keystone species that is a predator will

maintain the species diversity in a community

the number of species in a community is called the

species richness

within an ecosystem a tree is a


the sum total of a population's use of the biotic and abiotic resources of its habitat constitutes its


a series of reciprocal adaptations in two species defines


in a hypothetical food chain consisting of grass, grasshoppers, sparrows, and hawks, the grasshoppers are

primary consumers

non-native species that are introduced in new environments, spread far beyond the original point of introduction, and cause damage are called

invasive species

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.

energy, chemicals

in a food chain consisting of phytoplankton --> zooplankton --> fish-->fishermen, the fisherman are

tertiary consumers

the primary decomposers of a community are called


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

secondary succesion

in an ecosystem, about how much of the energy in producers will be available to secondary consumers in this ecosystem?

about 1%

given that CO2 is produced by respirations, why does the amount of CO2 in the atmosphere remain relatively constant?

CO2 is converted in photosynthesis to carbohydrates

which of the following substances is cycled between organic matter and abiotic reservoirs?


carbon mainly cycles between the biotic and abiotic worlds through the processes of

respiration and photosynthesis

which of the following statements about the phosphorus cycle is true?

phosphorus is cycled almost entirely within the soil, rather than transferred over long distance via the atmosphere

which of the following statements about the nitrogen cycle is true?

the nitrogen cycle requires different types of bacteria

which of the following represents a step in the nitrogen cycle?

nitrogen-fixing bacteria convert atmospheric nitrogen to ammonia

denitrifying bacteria convert ______ to _____.

nitrates, nitrogen gas

in experimental studies conducted at the Hubbard Brook Experimental Forest, it was found that

water runoff increased in the deforested areas

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

approximately _______ living species have been named and described.

1.8 million

the current rate of extinction may be as much as ______ times higher than at any other time in the past 100,000 years.


biodiversity considers

the genetic diversity within and between populations of a species

in the 2,000 years that humans have lived on Madagascar, the island has lost approximately ______ of its native species


currently, the single greatest threat to biodiversity is

habitat destruction due to humans

the three greatest current threats to biodiversity, in order starting with the greatest, are

habitat destruction, the introduction of invasive species, and overexploitation

chlorofluorocarbons (CFCs)

deplete the ozone layer

which of the following is likely consequence of the thinning of the ozone layer?

increases in skin cancer

large costal dead zones depleted of oxygen are primarily caused by

nutrient population

the increase in the concentration of a substance in the tissues of organisms as it is passed up a food chain is called

biological magnification

the top predators are most severely affected by pesticides such as DDT or manufacturing toxic substances such as PCBs, because they

consume prey in which pesticides or toxic substances are concentrated

approximately _____ of the prescriptions dispensed by US pharmacies contain substances drived from plants


global warming is the result of

rising concentration of greenhouse gases

average global temperature has risen _____ over the past 100 years.

0.8 degrees Celsius

the increase in global temperature resulting from the greenhouse effect is primarily due to

CO2 slowing the escape of heat from Earth

CO2 flooding into the atmosphere is absorbed by _____ and converted into biomass.

photosynthetic organisms

an organism's responses to climate change that result in phenotypic variation is called

phenotypic plasticity

fragmented populations

are likely to exhibit low levels of genetic diversity

some populations may avoid extinction as the climate changes, especially those with high genetic variability and short life spans, through

evolutionary adaptation

movement corridors are

strips or clumps of habitat that connect isolated fragments of habitat

which of the following statements about movement corridors is true?

movement corridors can connect otherwise isolated habitat patches

habitat fragmentation

often results from human activities

species found in only one place on Earth are called ____ species.


about one-third of all animal and plant species are concentrated on ______ of Earth's land.


the greatest challenge of facing the zoned reserve systems of Costa Rica is

the growing human population

which of the following statements about zoned reserves is incorrect?

the areas surrounding a zoned reserve are not to be used to support human populations

which of the following statements about protected areas is incorrect?

we now protect 25% of the land areas of the planet

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

with limited sources, conservation biologists need to prioritize their efforts. of the following choices, which should receive the greatest attention for the goal of conserving biodiversity?

a declining keystone species in a community

the aspect of conservation ecology concerned with returning degraded ecosystems (as nearly as possible) to their predegraded state is

restoration ecology

using living organisms to clean up polluted ecosystems is know as


the Kissimmee River Project is an

attempt to restore the natural wetlands associated with the Kissimmee River

the Kissimmee River Project is intended to

increase biodiversity of the region

sustainable development

depends on continued research and application to increase and apply knowledge to the biosphere

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