Bio Exam 4

Population

A group of individuals that belong to the same species and live in the same area

Community

All the different populations that live together in an area

Demography

Scientific study of human population and how they change

Population Size

the number of individuals in a population

population density

Number of individuals per unit area

Quadrat

A tool that provides an area where you can count the number of species within an ecosystem

mark and recapture

capturing and marking organisms, then recapturing them and counting how many are marked (used to determine population size)

species distribution

how a species is distributed throughout the environment

random distribution

distribution in which the location of members in a population is totally random

clumped distribution

a distribution in which individuals are found in groups or patches within the habitat

uniform distribution

Distribution where populations are spaced evenly

example of random distribution

plant seeds that spread by wind (dandelions)

example of uniform distribution

territorial animals (penguins)

example of clumped distribution

elephants or cattle

life tables

Age-specific summaries of survival patterns of a population.

mortality rate calculation

Total number that died in given time period divided by the total number

survivorship curves

a graph that represents the distinct patterns of species survival as a function of age

survivorship curve type 1

low death rates during early and middle life and an increase in death rates among older age groups

survivorship curve type 2

a constant death rate over the organism's life span

survivorship curve type 3

high death rates for the young and lower death rates for survivors

exponential growth

Growth pattern in which the individuals in a population reproduce at a constant rate

logistic growth

Growth pattern in which a population's growth rate slows or stops following a period of exponential growth

rN (K-N/K)

population growth equals

density dependent regulation

the regulation of population in which birth and death rates are dependent on population size

density-independent regulation

the regulation of population in which the death rate is independent of the population size

K-selected species

a species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity

r-selected species

a species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs

carrying capacity

Largest number of individuals of a population that a environment can support

age structure

number of males and females of each age in a population

Interactions between species

defense mechanisms

mechanical and chemical

mechanical defenses

a physical defense used to protect themselves from prey (spines, thorns, or a shell)

chemical defenses

Compounds released by prey to defend themselves from predators.

Camoflouge

when an organism blends into its environment

warning coloration

Bright coloration that warns predators that the potential prey is distasteful or even poisonous.

mimcry

when a organism tries to resmeble one organism to another organism or its surroundings for protection

Bateisan mimicry

when a harmless organism tries to make itself look like a harmful organism

Mullerian mimicry

two or more unpalatable species resemble each other

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

3 types of symbiosis

mutualism, commensalism, parasitism

mutualism

both organisms benefit

Commenalism

one species benefits and the other is not affected

Parasitism

One organism benefits and the other is harmed

foundation species

species that plays a major role in shaping a community by creating and enhancing a habitat that benefits other species

keystone species

a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

Succession

A series of predictable and orderly changes within an ecosystem over time.

ecosystems

A biological community of interacting organisms and their physical environment.

Abiotic

Non-living

biotic

living

Disturbances in Ecosystems

Any change in an ecosystem can become widespread and affect the ecosystem in unexpected ways

Equilibrium

a state in which opposing forces or influences are balanced.

Resistance

the ability of a environment to remain at equilibrium despite disturbances

resilience

how quickly a ecosystem recovers from a disturbance

food chains

Energy links between different organisms in an ecosystem based on feeding habits.

trophic levels

The successive levels of organisms consuming one another

food web

A community of organisms where there are several interrelated food chains

grazing food web

a type of food web in which the base are producers that are either plants on land or phytoplankton in the water

detrial food web

consists of a base of organisms that feed on decaying organic matter (dead organisms), called decomposers or detritivores.

Autotroph

An organism that makes its own food

Photoautotrophs

Organisms that use light as a source of energy to synthesize organic substances.

Chemoautotrophs

Organisms that use hydrogen sulfide or other chemicals as energy source instead of light.

gross primary productivity

total amount of energy produced by all the producers

net primary productivity

the amount of energy available to consumers in the ecosystem

Biomagnification

the increasing concentration of persistent, toxic substances in organisms at each successive trophic level.

biogeochemical cycle

the cycling of minerals and nutrients through the biotic and abiotic world

What are biogeochemical cycles?

water cycle, carbon cycle, nitrogen cycle, phosphorus cycle, and sulfur cycle

water cycle

The continuous process by which water moves from Earth's surface to the atmosphere and back

carbon cycle

The organic circulation of carbon from the atmosphere into organisms and back again

nitrogen cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere

sulfur cycle

The chemical and physical reactions by which sulfur moves into or out of storage and through the environment.

phosphorus cycle

The movement of phosphorus around the biosphere

terrestrial biomes

Biomes on land

Savanna

a grassy plain in tropical and subtropical regions, with few trees.

tropical rainforest

biome near the equator with warm climate wet weather and lush plant growth (most diverse)

tropical dry forest

A terrestrial biome characterized by relatively high temperatures and precipitation overall but with a pronounced dry season.

desert

An extremely dry area with little water and few plants

Chapparal

A scrubland biome of dense, spiny evergreen shrubs found at midlatitudes along coasts where cold ocean currents circulate offshore; characterized by mild, rainy winters and long, hot, dry summers.

temperate grassland

a community (or biome) that is dominated by grasses, has few trees, and is characterized by cold winters and rainfall that is intermediate between that of a forest and a desert

temperate forest

forest in a temperate region, characterized by trees that drop their leaves annually

Boreal Forest (Taiga)

Colder climate region, with coniferous trees; cold snowy winters and rainy summers that are warm enough to melt the snow

Arctic Tundra

This biome supports a low number of plant species, receives little rain, and plants have shallow root zones due to permafrost and wet soil.

marine biome

covers 70% of earth's surface; largest biome; temperatures vary from region to region; algae and plankton form the base of the food chain

pelagic realm

includes all open water

benthic realm

a seafloor, or the bottom of a freshwater lake, pond, river, or stream

photic zone

Portion of the marine biome that is shallow enough for sunlight to penetrate.

aphotic zone

dark layer of the oceans below the photic zone where sunlight does not penetrate

intertidal zone

Portion of the shoreline that lies between the high and low tide lines

neritic zone

Area of ocean that extends from the low-tide line out to the edge of the continental shelf

oceanic zone

vast open ocean from the edge of the continental shelf outward

coral reefs

The most diverse marine biome on Earth, found in warm, shallow waters beyond the shoreline.

Estuaries

wetlands formed where freshwater meets saltwater

endangered species

A species whose numbers are so small that the species is at risk of extinction

background extinction

gradual process of a species becoming extinct

Biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

Measuring Biodiversity

species richness (number of species)

our knowledge of current species is incomplete

types of biodiversity

genetic diversity, species diversity, ecosystem diversity, chemical diversity

genetic diverstiy

the total genetic information contained within all individuals of a population, species, or group of species

species diversity

Variety of different kinds of organisms that make up a community.

ecosystem diversity

variety of habitats, living communities, and ecological processes in the living world