Ecology Test Flashcards
ecology
the scientific study of interactions among organisms and between organisms and their environment, or surroundings
biosphere
the combined portions of the planet in which all life exists, including land, water, and air
How do ecologists understand relationships within the biosphere?
they ask questions about events and organisms that range in complexity from a single individual to the entire biosphere
species
a group of organisms so similar to one another that they can breed and produce fertile offspring
populations
groups of individuals that belong to the same species and live in the same area
communities
assemblages of different populations that live together in a defined area
ecosystem
a collection of all organisms that live in a particular place together with their nonliving environment
biome
a group of ecosystems that have the same climate and similar dominant communities
What do scientists use to conduct modern ecological research?
three basic approaches: observing, experimenting, and modeling. All of these approaches rely on the application of scientific methods to guide ecological inquiry.
sunlight
the main energy source for life on earth
what do organisms who don’t obtain their energy from sunlight use?
they rely on the energy stored in inorganic chemical compounds
autotrophs
plants, some algae, and certain bacteria. They can capture energy from sunlight or chemicals and use that energy to produce food
producers
make their own food
photosynthesis
carbon dioxide + Water, (light energy) = carbohydrates + oxygen
6CO2 + 6H2O , (light energy) = 6CH12O6 + 6O2
chemosynthesis
when organisms use chemical energy to produce carbohydrates
heterotrophs/consumers
organisms that rely on other organisms for their energy and food supply
herbivores
obtain energy by only eating plants
carnivores
obtain energy by eating meat/animals
omnivores
eat both plants and animals
detritivores
feed on plant and animal remains and other dead animal matter, called detritus
how does energy flow through an ecosystem?
in one direction, from the sun or inorganic compounds to autotrophs (producers) and then to various heterotrophs (consumers)
food chain
a series of steps in which organisms transfer energy by eating and being eaten
food web
links all the food chains in an ecosystem together
trophic level
each step in a food chain or food web
ecological pyramid
a diagram that shows the relative amounts of energy or matter contained in each trophic level in a food chain or web
how much energy is available at each trophic level?
only 10 percent is transferred to organisms at the next level
biomass
the total amount of living tissue within each given trophic level
pyramid of numbers
shows the relative number of individual organisms at each trophic level
biome
a complex of terrestrial communities that covers a large area and is characterized by certain soil and climate conditions and particular assemblages of plants and animals
tolerance
ability to survive and reproduce under conditions that differ from their optimal conditions
microclimate
the climate in a small area that differs from the climate around it
what are the major biomes?
tropical rain forest, tropical dry forest, tropical savanna, desert, temperate grassland, temperate woodland and shrubland, temparate forest, northwestern coniferous forest, boreal forest, and tundra.
what defines a biome?
a unique set of abiotic factors-particularly climate-and a characteristic assemblage of plants and animals
canopy
dense covering formed by the leafy tops of tall trees
understory
layer of shorter leaves and vines
deciduous
a tree that sheds its leaves during a particular season each year
coniferous
trees that produce seed-bearing cones, and most have leaves shaped like needles
humus
a material formed from decaying leaves and other organic matter that makes soil fertile
taiga
another name for a boreal forest
permafrost
a layer of permanently frozen subsoil
wetland
an ecosystem in which water either covers the soil or is present at or near the surface of the soil for at least part of the year
estuaries
wetlands formed where rivers meet the sea
photic zone
well lit upper layer of the ocean wear photosynthesis takes place
aphotic zone
below the photic zone and is permanently dark
besides the photic and aphotic zones, how do marine biologists divide the ocean into zones?
based on depth and distance from shore: the intertidal zone, the coastal ocean, and the open ocean
benthic zone
the ocean floor
tragedy of the commons
the idea that any resource, such as water in the ground or fish in the sea, that is free and accessible to everyone, may eventually be destroyed
how are environmental goods and services classified?
as either renewable or nonrenewable
renewable resource
can regenerate if they are alive or can be replaced by biochemical cycles if they are nonliving
nonrenewable resource
one that cannot be replenished by natural processes
sustainable development
a way of using natural resources without depleting them and of providing for human needs without causing longterm environmental harm
what can human activities affect?
the quality and supply of renewable resources such as land, forests, fisheries, air, and freshwater
soil erosion
the wearing away of surface soil by water and wind
desertification
a combination of farming, overgrazing, and drought has turned once productive areas into deserts
deforestation
loss of forests
aquaculutre
the raising of aquatic animals for human consumption
smog
a mixture of chemicals that occurs as a gray-brown haze in the atmosphere
pollutant
a harmful material that can enter the biosphere through the land, air, or water
