cell theory
idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells
Eukaryotic cell
cell that has a nucleus and other membrane-bound organelles
prokaryotic cell
A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
species
A group of similar organisms that can breed and produce fertile offspring.
ecology
Scientific study of interactions among organisms and between organisms and their environment
population
A group of individuals that belong to the same species and live in the same area
habitat
the natural home or environment of an animal, plant, or other organism.
community
All the different populations that live together in an area
ecosystem
A biological community of interacting organisms and their physical environment.
biomes
a broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions.
natural greenhouse effect
Heat buildup in the atmosphere due to the presence of 'greenhouse' gases like carbon dioxide, methane, and water vapor.
abiotic
Non-living
biotic
living
range of tolerance
the limits to the abiotic conditions that a species can tolerate
limiting factor principle
the distribution of an organism or the structure of an ecosystem can be explained by the control exerted by the single factor (such as temperature, light, water) that is most deficient, that is, that falls below the levels required
producers/autotrophs
Organisms that make their own food (photosynthesis or chemosynthesis)
consumers/heterotrophs
obtain energy by consuming other organisms
omnivore
An animal that eats both plants and animals
decomposers/detritivores
decomposers decompose dead material by chemically breaking it down. detritivores feed directly on the meat of dead animals
aerobic respiration
Respiration that requires oxygen
anaerobic respiration
Respiration in the absence of oxygen. This produces lactic acid.
Fermentation
Process by which cells release energy in the absence of oxygen
food chain
A series of steps in which organisms transfer energy by eating and being eaten
food web
A community of organisms where there are several interrelated food chains
biomass
total amount of living tissue within a given trophic level
ecological effieciency
the proportion of consumed energy that can be passed from one trophic level to another
gross primary productivity
the amount of sugar that the plants produce in photosynthesis
Net Primary Productivity (NPP)
The energy captured by producers in an ecosystem minus the energy producers respire
biodiversity
the variety of life in the world or in a particular habitat or ecosystem.
species diversity
The number and relative abundance of species in a biological community.
ecosystem diversity
variety of habitats, living communities, and ecological processes in the living world
functional diversity
Biological and chemical processes or functions such as energy flow and matter cycling needed for the survival of species and biological communities
evolution
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.
natural selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
adaptations
Changes in physical structure, function, or behavior that allow an organism or species to survive and reproduce in a given environment.
mutations
a random error in gene replication that leads to a change
differential reproduction
Phenomenon in which individuals with adaptive genetic traits produce more living offspring than do individuals without such traits.
speciation
Formation of new species
geographic isolation
form of reproductive isolation in which two populations are separated physically by geographic barriers such as rivers, mountains, or stretches of water
reproductive isolation
Separation of species or populations so that they cannot interbreed and produce fertile offspring
background extinction
gradual process of a species becoming extinct
mass extinction
event in which many types of living things become extinct at the same time
species richness
the number of different species in a community
generalist species
Species that does not rely on a single source of prey
specialist species
consumer that eats only one type of organism
native species
Species that normally live and thrive in a particular ecosystem
invasive species
species that enter new ecosystems and multiply, harming native species and their habitats
indicator species
Species that serve as early warnings that a community or ecosystem is being degraded.
keystone species
A species that influences the survival of many other species in an ecosystem
foundation species
species that plays a major role in shaping a community by creating and enhancing a habitat that benefits other species
interspecific competition
competition between members of different species
competitive exclusion principle
Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time
predation
An interaction in which one organism kills another for food.
coevolution
Process by which two species evolve in response to changes in each other
parasitism
A relationship between two organisms of different species where one benefits and the other is harmed
mutualism
A relationship between two species in which both species benefit
commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
resource partitioning
The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species
population dynamics
The study of how complex interactions between biotic and abiotic factors influence variations in population size.
intrinsic rate of increase
rate at which the population of a species would grow if it had unlimited resources
biotic potential
The maximum rate at which a population could increase under ideal conditions
environmental resistance
All the limiting factors that act together to limit the growth of a population.
carrying capacity
Largest number of individuals of a population that a environment can support
reproductive time lag
the period needed for the birth rate to fall and the death rate to rise in response to resource overconsumption
r vs k selected species
-Cane toads, mosquitoes: small body size, early maturity, short life span, large broods, little or no parental care
-Humans or mammals: do not produce large numbers of offspring, long life spans, slow development, late reproduction, large body size, paren
founder effect
genetic drift that occurs after a small number of individuals colonize a new area
demographic bottleneck
A population founded when just a few members of a species survive a catastrophic event or colonize new habitat geographically isolated from other members of the same species.
genetic drift
random change in allele frequencies that occurs in small populations
inbreeding
Continued breeding of individuals with similar characteristics
minimum viable population size
The number of individuals needed for long-term survival of rare and endangered species
density dependent factors
limiting factor that depends on population size
independent population control
affected by factors that affect birth and death rates such as abiotic factors and environmental factors
stable
A species whose population size fluctuates slightly above
and below its carrying capacity
irruptive
population growth may occasionally surge, or irrupt, to a high peak and then crash to a more stable lower level or, in some cases, to a very low, unstable level.
cyclic
populations fluctuate and regular cyclic or boom-and-bust cycles
irregular
population fluctuates randomly with no recurring pattern
primary succession
An ecological succession that begins in an area where no biotic community previously existed
secondary succession
Succession following a disturbance that destroys a community without destroying the soil
early successional species/pioneer species
usually characterized by high growth rates, smaller size, high degree of dispersal, and high rates of per capita population growth (ex. lichen, algae, fungi)
midsuccessional plant species
Grasses and low shrubs that are less hardy than early successional plant species. (ex. red-osier dogwood, salmonberry, Pacific nine-bark, trailing blackberry, and willows)
late successional plant species
Mostly trees that can tolerate shade and form a fairly stable complex forest community. (ex. white spruce, Canadian hemlock, Pacific silver fir, coast redwood)