Exam 4 study guide

most commonly individuals show a ___ distribution within their habitat

clumped

the rate at which population size grows or declines depends on the rate of

births, deaths, immigration, emmigration, and available resources

Suppose 200 fish are marked and released in a pond. The following week, 200 fish are caught and 100 of them have marks. There are about ___ fish in this pond

400

For a given species, the maximum rate of increase per individual under ideal conditions is its

biotic potential

___ is a density-independent factor that influences population growth.

harsh weather

Species that live in unpredictable habitats are more likely to show traits that are favored by

r-selection

When human or animal predators target the largest members of a prey population, prey individuals who ___ are at a selective advantage

mature sexually while small

Compared to the less developed countries, the highly developed ones have a higher

resource consumption rate

All members of a cohort are the same

age

The ecological footprint of a person in the United States is about that of a person in India.

nine times

The demographic transition model predicts a decline in population during the ___ stage

postindustrial

A population in which the total fertility rate exceeds the replacement fertility rate is

increasing in size

The type of physical environment in which a species typically lives is its

habitat

___ can lead to resource partitioning

interspecific competition

By a currently favored hypothesis, species richness of a community is greatest when physical disturbances are of ___ intensity and frequency.

intermediate

With ___ one species evolves to look like another.

mimicry

Growth of a forest in an abandoned corn field is an example of

secondary succession

Species richness is greatest in communities ___

near the equator

If you remove a species from a community, the population size of its main ___ is likely to increase

competitor

___ steal parental care

brood parasites

The oldest established land communities are

in the tropics

Biological control of pest species

uses natural enemies

In most ecosystems, the primary producers use energy from __ to build organic compounds

sunlight

Organisms at the lowest trophic level in a tallgrass prairie are all

autotrophs

All organisms at the top trophic level

would be at the top of an energy pyramid

Primary productivity is affected by

nutrient availability, amount of sunlight, and temperature

Efficiency of energy transfers in aquatic ecosystems is typically higher than in land ecosystems because

algae do not make lignin

Most of Earth’s freshwater is

frozen as ice

Earth’s largest carbon reservoir is

sediments and rocks

Carbon is released into the atmosphere by

burning fossil fuels

Greenhouse gases

slow the escape of heat energy from Earth into space, are produced by natural and human activities, and are at higher levels than they were 100 years ago

The ___ cycle is a sedimentary cycle

phosphorous

Earth’s largest phosphorus reservoir is

sedimentary rock

Plant growth requires uptake of ___ from the soil

nitrogen and phosphorous

Nitrogen fixation converts _ __to ___ .

nitrogen gas; ammonia

Burning fossil fuel releases ___ into the air.

carbon dioxide; nitrous oxide

the Northern Hemisphere is most tilted toward the sun on the

june solstice

Warm air _ __and it holds ___ water than cold air

rises; more

a rain shadow is a reduction in rainfall

on the inland side of a coastal mountain range

___ have a deep layer of nutrient-rich topsoil.

grasslands

Biome distribution depends on

climate, elevation, and soils

grasslands most often are found

in interior of continents

permafrost underlies

arctic tundra

Chemoautotrophic bacteria and archaea are the main primary producers for food webs

at hydrothermal vents

What biome borders boreal forest to the north?

tundra

Unrelated species in geographically separated parts of a biome may resemble one another as a result of

morphological convergence

Passenger pigeons were driven to extinction

by overharvesting

An ___ species has population levels so low it is at great risk of extinction in the near future

endangered

Sulfur dioxide released by coal-burning power plants contributes to

acid rain

As a result of ___ an old animal usually has more pollutants in its body than a young one.

bioaccumulation

With biological magnification, a ___ will have the highest pollutant load.

top-level consumer

An increase in the size of the ozone hole would be expected to

increase skin cancers

Global climate change is causing

glacial melting

A highly threatened region that is home to many unique species is a(n)

biodiversity hot spot

Biodiversity refers to

genetic, species, and ecosystem diversity

Restoring a marsh that has been damaged by human activities is an example of

ecological restoration