AP Biology 4.5 Exam

Biosphere

Biosphere

upper and lower limits where life is possible

Hydrosphere

layer covering ¾ of earth; moderates temperature to keep it suitable for life

Herbivore

eats only plants

Omnivores

eat plant and animal foods

Detrivores

feed on detritus

Autotroph

producer; makes its own food; energy flow in an ecosystem begins with them

Energy flow

moves in one direction because it is no longer useful when converted to heat

Net primary productivity

amount of stored energy left in plant material and available to consumers after the plant used energy it needs for life processes

Trophic levels

about 10% of energy in one level is available to organisms in the next level as one moves up a food pyramid

Food chains

only about 5% - 20% efficient at each step which limits how many organisms can be in the chain; top carnivores will get limited energy so the higher you go, the less energy is available

Water cycle

involves the processes of precipitation, evaporation, transpiration, runoff, and wind

Greenhouse effect

sunlight enters our atmosphere, is absorbed, and reradiated back as longer wavelength heat waves which can be trapped by gases in the atmosphere

Ozone

O3 molecule; holes form in the ozone layer due to chlorofluorocarbons (CFCs)

Eutrophic

aquatic environment rich in nutrients that tends to have large populations of algae (algal blooms)

El Nino

leads to unusual warming in surface waters; when it fails, there is stagnation, poor fishing, and global climate pattern changes

Upwelling

ocean currents bring rich nutrients to the surface

Climate

includes temperature, topography, precipitation, and variations in solar radiation distribution

Flagship species

revered by humans due to their appearance

Conservation

supports the following ethical principles: biodiversity is desirable for the biosphere and humans; biodiversity has value in and of itself regardless of any practical human benefits; complex interactions of ecosystems support biodiversity and are desirable; extinctions due to human actions are undesirable

Biological diversity

how many different species exist in the biosphere; many species that are in danger of extinction have not been studied, and some may contain potentially useful characteristics for domestication and use; 10% to 20% of all species now living may become extinct in the next twenty to fifty years; examples: a 4-square-mile area of rain forest holds more tree species than are found across the continental United States; migratory birds often depend on the diverse habitats on several continents

Biodiversity hotspot

contains a high concentration of unique species

Biodiversity frontier

contains many more species that previously thought

Extinction

the last remaining individual of a species dies out; there are a variety of causes to extinctions and an animal or plant may go extinct due to different combinations of factors

Exotic species

introduced species which can become invasive; occurs when new settlers arrive in an area; it can be accidentally or intentionally introduced and can occur through agricultural and horticultural activities

Acid rain

occurs when exhaust from cars and factories combines with water in the atmosphere to produce a weak acid

Global warming

having a serious impact on coral reefs since a small temperature increase can cause them to expel algae and turn white (coral bleaching) which means they stop growing and reproducing

Overfishing

many areas have been overexploited leading to drastic decreases in fish populations

Metapopulation

formed when habitats are fragmented; populations are subdivided into several small and isolated groups to form the metapopulation

Keystone species

critical species for an ecosystem; if they are removed the ecosystem can collapse

Source population

a species lives in favorable conditions where its birthrate exceeds its death rate so it can provide input to other fragmented populations

Sink population

a species survives in unfavorable conditions where its death rate exceeds its birthrate so it must have input from other fragmented populations

Edge effect

patches get smaller and organisms live well deep inside large patches and are exposed to less favorable conditions

Population viability analysis

calculates the minimum number of individuals needed to keep a population thriving

Habitat restoration plan

researchers identify the factors causing habitat decline and develop a procedure to fix them

Human overpopulation

a primary challenge of conservation because we use too many resources, produce too much waste, and damage the environment