endotherms

generate their own body heat through metabolism

ectotherms

lack internal mechanisms for body temperature control, regulate behaviorally with cool or warm places

behavior

how organisms cope with their environments

instinct

inborn, unlearned behavior

learning

a change in behavior brought about by an experience

imprinting

a form of learning that occurs during a brief period of time, usually early in an organism's life (parental, sexual, song)

critical period

a window of time when the animal is sensitive to certain aspects of the environment

habituation

form of learning that occurs when an animal learns not to respond to a stimulus

circadian rhythm

a natural oscillation that repeats roughly every 24 hours. internal alarm clocks

pheromones

chemical signals between members of the same species that stimulate olfactory receptors and affect behavior

agonistic behavior

aggressive social behavior as a result of competition for food / resources

dominance hierarchies (pecking orders)

social behavior in which members in a group establish which is the most dominant (competition and tension become reduced after it is decided)

territoriality

the behavioral, psychological, or legal attempt by individuals, groups, or animals to claim, control, and defend specific geographic areas, resources, or spaces (occurs when food and nesting sites in short supply)

altruistic behavior

unselfish behavior that benefits another organism in the group at the individual's expense because it advances the genes of the group

symbiotic relationship

a close, prolonged association between two or more different biological species

mutualism

symbiotic relationship in which both organisms win

commensalism

symbiotic relationship in which one organism lives off another with no harm to the host

parasitism

symbiotic relationship in which organism harms host

photoperiodism

plants flower in response to changes in the amount of daylight and darkness they receive

tropism

a turning in response to a stimulus

phototropism

plants respond to sunlight (bend towards light)

gravitropism

plants respond to gravity (stems = negative gravitropism, move up; roots = positive gravitropism, move down)

thigmotropism

plants respond to touch (grow around objects)

auxins

plant hormone that promotes growth, phototropism, cell elongation, and fruit development (usually at tip of plant)

gibberellins

plant hormone that promotes cell elongation

cytokinins

plant hormone that promotes cell division and differentiation

ethylene

plant hormone that induces leaf abscission and promotes fruit ripening

abscisic acid

plant hormone that inhibits abscission and promotes bud and seed dormancy

ecology

the study of interactions between living things and their environments

biosphere

entire part of Earth where living things exist

ecosystem

interaction of living and nonliving things

community

a group of populations interacting in the same area

population

a group of individuals that belong to the same species and interbreed

biotic factors

living things

abiotic factors

nonliving things like water, humidity, temperature, soil / atmosphere composition, and light radiation

carbon cycle

the continuous, natural process by which carbon atoms move between the Earth's atmosphere, oceans, soil, rocks, and living organisms

niche

an organism's position or function in a community

food chain

the way different organisms depend on one another for food

producers (autotrophs)

photosynthetic or chemosynthetic organisms, make own food

consumers (heterotrophs)

find energy sources in the outside world (do not produce themselves)

primary consumers

eat producers (herbivores)

secondary consumers

eat producers and primary consumers (carnivores and omnivores)

tertiary consumers

eat primary, secondary, and producers (everything below in the trophic pyramid)

decomposers

break things down

keystone species

one organism particularly important to an ecosystem

10% rule

in a food chain, only 10 percent of energy is transferred from one level to the next

ecological pyramid

represents energy flow, biomass, and members within an ecosystem (highest = least biomass, energy, and numbers)

bioaccumulation

the gradual buildup of persistent, harmful chemicals (like mercury or pesticides) in an organism's tissues faster than they can be metabolized or excreted

biomagnification

the increasing concentration of toxic, persistent substances (like mercury or DDT) in the tissues of organisms at higher trophic levels within a food chain

Simpson's diversity index

measure of the diversity of a community, greater = more diverse

population growth

number of births - number of deaths divided by the size of the population: r = (births-deaths) / N OR (Change in Population Size / Change in Time) = Birth Rate - Death Rate

carrying capacity

the maximum number of individuals of a species that a habitat can support

population density

the concentration of individuals within a species in a specific geographic locale

density independent factors

affect population, regardless of density (e.g. severe storms, extreme climates)

density dependent factors

effects depend on population density (e.g. resource depletion, competition, predation)

r-strategists

thrive in areas that are barren or uninhabited , colonize and produce quickly (common weeds, dandelions, bacteria)

k-strategists

best suited for survival in stable environments (large animals with long lifespans)

ecological succession

the predictable procession of plant communities over a relatively short period of time (decade or centuries)

primary succession

the process of ecological succession in which no previous organisms have existed (lichen and seres)

sere

A complete succession of plant communities, which results in the climax community. A sere is composed of a series of different plant communities that change with time. These communities are known as seral stages or seral communities.

pioneer organisms

resilient species that are the first to colonize barren environments, or to repopulate disrupted biodiverse steady-state ecosystems

climax community

final community after ecological succession, MOST STABLE

secondary succession

when a new community develops where another community has been destroyed or disrupted, develop more quickly than primary

greenhouse effect

atmospheric gases (water vapor, carbon dioxide, methane, and nitrous oxide) trap heat near Earth's surface, keeping the planet warm enough to sustain life

ozone depletion

the steady decline of the Earth's stratospheric ozone layer, caused by human-made chemicals like chlorofluorocarbons (CFCs) that release chlorine and bromine in the atmosphere

acid rain

any form of precipitation—rain, snow, fog, or dust—that contains high levels of sulfuric and nitric acids, typically with a pH below 5.6

desertification

when a land is overgrazed by animals, it turns grasslands into deserts and reduces available habitats for organisms

deforestation

when forests are cleared (especially by slash and burn method), erosion, floods, and changes in weather patterns occur

pollution

toxic chemicals in the environment like DDT and pesticides

reduction in biodiversity

as different habitats have been destroyed, many plants and animals have become extinct that could have provided medicines or products

introduction and spread of disease

human travel disrupts habitats and brings disease, immediate selective pressures that can leave an ecosystem forever changed