52 Flashcards
ecology
scientific study of interactions between organisms and the environment
climate
long-term prevailing weather conditions in a given area
five levels of ecological study:
organisms, populations, communities, ecosystems, and the biosphere.
Abiotic
nonliving factors (light, water, nutrients)
biotic
living factors
Weather
conditions of the atmosphere are over a short period of time
Discuss some of the factors that influence climate
- Latitude. Depending on how close or how far it is to the equator.
- Ocean currents. Certain ocean currents have different temperatures
- Wind and air masses. Heated ground causes air to rise which results in lower air pressure
- Elevation
- Relief
- Nearness to water.
biome
Biomes are typically characterized based on the dominant plant and animal species found in a certain geographic area
How are biomes characterized?
Temperature and precipitation are what determine the geographic distribution of a biome, which species can live there.
which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems?
landscape ecology
which lake zone would be absent in a very shallow lake?
aphotic zone
which of the following is characteristic of most terrestrial biomes?
vegetation demonstrating vertical layering
the oceans affect the biosphere in all of the following ways except
regulating the pH of freshwater biomes and terrestrial groundwater
which statement about dispersal is false?
dispersal occurs only on an evolutionary time scale
when climbing a mountain, we can observe transitions in biological communities that are analogous to the changes
in biomes at different latitudes
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?
tropical rain forest
if the direction of earths rotation reversed, the most predictable effect would be:
winds blowing from west to east along the equator
aphotic zone
is the portion of a lake or ocean where there is little or no sunlight.
An ecologist might conduct research to answer which of the following questions?
How do tapeworms cope with life in the human intestine?
The sum of all Earth’s ecosystems is called the __________.
biosphere
An immature frog (a tadpole) lives in a pond or lake. The adult frog lives on land, and it possesses special adaptations that permit it to survive in a terrestrial environment. These special adaptations _____.
help prevent the adult frog”s body from drying out
Why are many of the world’s deserts located at latitudes of about 30° north and south?
Dry air, originating at the equator, descends toward Earth”s surface at about 30° north and south.
Earth’s biosphere is not completely self-contained (or closed) because _____.
plants, algae, and photosynthetic bacteria obtain energy from sunlight, and heat escapes from the biosphere into space
When people speak of the “rain shadow” of the California Coast Range, they are referring to _____.
the scarcity of rain on the eastern flank and adjacent lowlands compared with the western flank
Which one of the following statements about biomes is correct?
The major factors affecting the distribution of biomes are temperature and precipitation.
Communities that exist in the aphotic zone ultimately depend on food molecules manufactured by chemoautotrophic bacteria or _____.
algae and cyanobacteria that live in the photic zone
After eutrophication (an increase in nutrients) due to sewage contamination, a lake often becomes inhospitable to fish. Why?
Nutrient input to a lake causes the explosive growth of algal and cyanobacterial populations. Decomposition of dead algae and cyanobacteria by bacteria results in the depletion of oxygen in the water, which leads to the death of all the fish
Plankton consists of _____.
algae, cyanobacteria, and animals that drift near the surfaces of oceans, lakes, ponds, rivers, and streams
Which one of the following is characteristic of oligotrophic lakes?
few littoral plants, a low density of phytoplankton
oligotrophic
(especially of a lake) relatively low in plant nutrients and containing abundant oxygen in the deeper parts.
Rooted plants are found only in the __________ zone of a lake.
littoral
Below the photic zone of the ocean, __________.
food chains are detritus-based
Different species that belong to the same biome, but occur in widely separated geographic regions, often appear similar due to _____.
convergent evolution
Permafrost is characteristic of the _____.
tundra
A coniferous forest would be characterized by _____.
coniferous trees
Most of the best agricultural soils in the United States occur in areas that were formerly __________.
grassland
A trophy room contains the heads of a cape buffalo, a zebra, and an impala, all shot within a day’s radius from a single hunting camp in Africa. This camp was probably located in a __________.
savanna
Which one of the following choices does NOT correctly pair a biome with some of its characteristics?
savanna: long, cold winters; abundant precipitation throughout the year
Which one of the following biomes is dominated by gymnosperm or conifer trees (pines, firs, spruces)?
taiga
Of these biomes, vertical stratification (layers of plants) is most pronounced in the __________.
tropical rain forest
Grasses are a dominant part of the plant community in the __________.
savanna
How does permafrost affect the tundra vegetation?
It prevents roots from penetrating very far into the ground.
Arboreal animals are most characteristic of the __________.
tropical rain forest
Arboreal
(chiefly of animals) living in trees.
Huge herds of bisons and pronghorn antelopes once roamed the North American __________.
grasslands
Which one of the following pairs of biomes are characterized by relatively simple food webs (a low biological diversity)?
tundra and desert
In which one of the following biomes would you expect decomposers to work most rapidly and efficiently?
tropical rain forest
community
includes all populations, representing multiple species, in the same region.
Because Earth’s surface is curved, the sun’s rays are spread over a______ with increasing distance from the equator. Temperatures are therefore coldest at the poles.
greater surface area
what happens at 30 degrees latitude
Dry air descends around 30° latitude, absorbing moisture from the land. Most deserts are near this latitude.
what happens at 60 degrees latitude
At about 60° latitude, the air mass has warmed and absorbed enough moisture from the land to rise and cause precipitation.
tropical rainforest
major threat?
warm and moist year-round
vertically layered
major threat: deforestation
desert
hot or cold, but always dry
savannas
major threat?
dry most of the year and warm year-round
• Grasslands with sparse tree cover are called savannas.
threat: grazing from livestock
scrublands/chaparral
Characterized by warm, dry summers and cool, moist winters (california)
Major threat: Human homes built in chaparral harm endangered wildlife and burn periodically.
Temperate Grasslands
Winters are cold and dry, while summers are wet and hot
Temperate Broadleaf Forests
Winters are cool, while summers are hot and humid; significant precipitation falls year round as rain and snow
Northern Coniferous Forest
The northern coniferous forest, or TAIGA, extends across northern North America and Eurasia and is the largest terrestrial biome on Earth
• Winters are cold and long while summers may be hot
tundra
covers expansive areas of the Arctic; alpine tundra exists on high mountaintops at all latitudes
• Winters are long and cold while summers are relatively cool; precipitation varies
intertidal zone
- The ocean meets land
- The shore is pounded by waves during high tide
- The bottom is exposed to the sun and drying winds during low tide
oceanic pelagic biome
vast realm of open blue water, constantly mixed by wind-driven oceanic currents
• This biome covers approximately 70% of Earth’s surface
• Phytoplankton and zooplankton are the dominant organisms in this biome; also found are free- swimming animals
A dinoflagellate, called ____ , live within the tissues of the corals
zooxanthella
The coral reef biome occurs in the _____ of warm tropical waters, in scattered locations around the globe.
photic zone
can partake in photosynthesis
major threat to coral reefs:
global warming and pollution
Marine Benthic Zone
consists of the seafloor below the surface waters of the coastal, or neritic, zone and the offshore pelagic zone
Oligotrophic lakes
are nutrient-poor and generally oxygen-rich
Eutrophic lakes
are nutrient-rich and often depleted of oxygen if ice covered in winter
Rooted and floating aquatic plants live in the shallow and well-lighted ______
littoral zone
major threats to estuaries
- Landfills
- Nutrient pollution
- Alteration of freshwater inflow
- The introduction of non-native species
