ap env science big vocab Test and Flashcards

abyssal zone

the deepest region of the ocean, marked by extremely cold temperatures and low levels of dissolved oxygen, but high levels of nutrients because of the decaying plant and animal matter that sinks down from the zones above

ammonification

the production of ammonia or ammonium compounds in the decomposition of organic matter, especially through the action of bacteria

assimilation

the process in which plants absorb ammonium (NH3), ammonia ions (NH4+), and nitrate ions (NO3) through their roots

bathyal zone

the middle region of the ocean, characterized by less density of organisms because it does not receive enough light to support photosynthesis

benthic zone

the surface and sub-surface layers of the river-, lake-, pond-, or streambed, characterized by very low temperatures and low oxygen levels

chaparral

scrub forest or shrubland; a biome characterized by moderate precipitation, shallow or infertile soil, small trees with large, hard evergreen leaves, and spiny shrubs

chemotrophs

autotrophic bacteria that use chemosynthesis to produce energy in anaerobic environments

coniferous forest (taiga)

a biome characterized by moderate precipitation, acidic soil, and coniferous trees

deciduous forest

a biome characterized by adequate precipitation, rich soil with high organic content, and hardwood trees

denitrification

the process by which specialized bacteria (mostly anaerobic bacteria) convert ammonia to NO3, NO2, and N2, which are released back into the atmosphere

epilimnion

the uppermost and thus the most oxygenated layer of freshwater

euphotic zone

the photic, upper layers of ocean water; the ____ zone is the warmest region of ocean water and has the highest levels of dissolved oxygen

eutrophication

warm water becoming overly enriched with minerals and nutrients to the point that excessive growth of algae and other phytoplankton occurs (an algal bloom)

Gause’s principle

states that no two species can occupy the same niche at the same time, and that the species that is less fit to live in the environment will either relocate, die out, or occupy a smaller niche

hypolimnion

the lower, colder, and denser layer of freshwater

Law of the Minimum

states that living organisms will continue to live, consuming available materials until the supply of these materials is exhausted

limnetic zone

the surface of open ocean water; the region that extends to the depth that sunlight can penetrate

littoral zone

ocean zone beginning with the very shallow water at the shoreline and extending to the depth at which rooted plants stop growing

nitrification

the process in which soil bacteria convert ammonium (NH4+) to a form that can be used by plants: nitrate, or NO3–

nitrogen fixation

the conversion of atmospheric nitrogen into compounds, such as ammonia, by natural agencies or various industrial processes

profundal zone

the depths; ocean water that is too deep for sunlight to penetrate. Because this zone is aphotic (a place where light cannot reach), photosynthesizing plants and animals cannot live in this region

saprotrophs

decomposers that use enzymes to break down dead organisms and absorb the nutrients

thermocline

a layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt

tropical rainforest

a biome characterized by abundant rain, poor quality soil, and tall trees with few lower limbs, vines, epiphytes, and plants adapted to low light intensity

tundra

a biome characterized by very low precipitation, permafrost, and herbaceous plants

Flashcards: ap env science big vocab