BE 307 Midterm

The fraction of electromagnetic radiation reflected after striking a surface
A major division of microorganisms. Like bacteria, Archaea are single-celled organisms lacking nuclei and are therefore prokaryotes, classified as belonging to kingdom Monera in the traditional five-kingdom taxonomy.

Microscopic organisms whose single cells have neither a membrane-bounded nucleus nor other membrane-bounded organelles like mitochondria and chloroplasts.
Cambrian Explosion
Between about 570 and 530 million years ago, when a burst of diversification occurred, with the eventual appearance of the lineages of almost all animals living today.
An ion with a positive charge.
A phylum of Bacteria that obtain their energy through photosynthesis.

They are often referred to as blue-green algae, although they are in fact prokaryotes, not algae.

A single-celled or multicellular organism whose cells contain a distinct membrane-bound nucleus.
Microorganisms belonging to the domains Bacteria and Archaea that can live and thrive in environments with extreme conditions such as high or low temperatures and pH levels, high salt concentrations, and high pressure.
geochemical cycling
Flows of chemical substances between reservoirs in Earth’s atmosphere, hydrosphere (water bodies), and lithosphere (the solid part of Earth’s crust).

An organism that requires organic substrates to get its carbon for growth and development.
negative feedback
When part of a system’s output, inverted, feeds into the system’s input; generally with the result that fluctuations are weakened.
An array of reactions involving several different types of chemical conversions: (1) loss of electrons by a chemical, (2) combination of oxygen and another chemical, (3) removal of hydrogen atoms from organic compounds during biological metabolism, (4) burning of some material, (5) biological metabolism that results in the decomposition of organic material, (6) metabolic conversions in toxic materials in biological organism, (7) stabilization of organic pollutants during wastewater treatment, (8) conversion of plant matter to compost, (9) decomposition of pollutants or toxins that contaminate the environment.
The largest generally accepted groupings of animals and other living things with certain evolutionary traits.
plate tectonics
A concept stating that the crust of the Earth is composed of crustal plates moving on the molten material below.

Organisms without a cell nucleus, or any other membrane-bound organelles. Most are unicellular, but some prokaryotes are multicellular. The prokaryotes are divided into two domains: the bacteria and the archaea.
radiometric dating
A technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. It is the principal source of information about the age of the Earth and a significant source of information about rates of evolutionary change.
Snowball Earth
Hypothesis that proposes that the Earth was entirely covered by ice in part of the Cryogenian period of the Proterozoic eon, and perhaps at other times in the history of Earth
statigraphic record
Sequences of rock layers. Correlating the sequences of rock layers in different areas enables scientists to trace a particular geologic event to a particular period.

The process in which one plate is pushed downward beneath another plate into the underlying mantle when plates move towards each other.
atmospheric (adiabatic) lapse rate
The constant decline in temperature of an air parcel as it rises in the atmosphere due to pressure drop and gas expansion.
the fraction of electromagnetic radiation reflected after striking a surface
Describes an organism that is able to live without oxygen. Also used to describe environments that are devoid of gaseous or dissolved molecular oxygen.
angular momentum
The measure of the extent to which an object will continue to rotate about a point unless acted upon by an external torque.
capable of floating
the transfer of heat by a moving fluid, such as air or water
the flowing together of air masses
Coriolis force
the apparent force, resulting from the rotation of the Earth, that deflects air or water movement
removal of trees and other vegetation on a large scale, usually to expand agricultural or grazing lands
dew point
the temperature at which air becomes saturated with water vapor and condenses into water called dew
dry adiabatic lapse rate
condition of a system in which inflow of materials or energy equals flow
El Nino Souther Oscillation (ENSO)
A global event arising from large-scale interactions between the ocean and the atmosphere, usually an oscillation in the surface pressure (atmospheric mass) between the southeastern tropical Pacific and the Australian-Indonesian regions.
Corrective information or a signal generated within a self-regulating system or process that is intended to induce a change in that system or process.

geostrophic flow
A current in the atmosphere in which the Coriolis force and the pressure gradient are in balance.
greenhouse gases
Atmospheric gases or vapors that absorb outgoing infrared energy emitted from the Earth naturally or as a result of human activities. Greenhouse gases are components of the atmosphere that contribute to the Greenhouse effect.

Hadley circulation
A general circulation pattern in which air rises near the equator, flows north and south away from the equator at high altitudes, sinks near the poles, and flows back along the surface from both poles to the equator.
-Lines on a map connecting points having the same barometric pressure.
jet stream
Fast flowing, relatively narrow air currents found in the atmosphere at around 11 kilometres (36,000 ft) above the surface of the Earth, just under the tropopause.

latent energy
Energy supplied externally, normally as heat, that does not bring about a change in temperature.
moist adiabatic lapse rate
The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere. The moist adiabatic lapse rate is not a constant like the dry adiabatic lapse rate but is dependent on parcel temperature and pressure.

Montreal Protocal on Substances that Deplete the Ozone Layer
A 1987 international agreement, subsequently amended in 1990, 1992, 1995, and 1997, that establishes in participating countries a schedule for the phaseout of chloroflourocarbons and other substances with an excessive ozone-depleting potential.
natural fires
A rapid, persistent chemical reaction that releases heat and light; especially the combination of any substance that’s easy to burn with oxygen that releases heat. Most natural fires start when a lightening bolt strikes a tree trunk and knocks the tree down.
relative humidity
The ratio of the amount of water vapor present in a specified volume of air to the maximal amount that can be held by the same volume of air at a specified temperature and pressure.
Metabolism of an individual cell, tissue, or organism that results in the release of chemical energy derived from organic nutrients.
Any hooved animal that digests its food in two steps, first by eating the raw material and regurgitating a semi-digested form known as cud, then eating (chewing) the cud, a process called ruminating.
Habitats that serve to trap or otherwise remove chemicals such as plant nutrients, organic pollutants, or metal ions through natural processes.
biological pump
The sum of a suite of biologically-mediated processes that transport carbon from the surface euphotic zone (the depth of the water that is exposed to sufficient sunlight for photosynthesis to occur) to the ocean’s interior.

A relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic system. Algal blooms may occur in freshwater or marine environments.
The upward force on an object produced by the surrounding fluid (i.

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e., a liquid or a gas) in which it is fully or partially immersed, due to the pressure difference of the fluid between the top and bottom of the object.

compensation depth
Depth at which light intensity reaches a level at which oxygen evolved from a photosynthesizing organism equals that consumed by its respiration.
compensation zone
The point at which there is just enough light for a plant to survive. At this point all the food produced by photosynthesis is used up by respiration. For aquatic plants, the compensation point is the depth of water at which there is just enough light to sustain life (deeper water = less light = less photosynthesis).

Ekman transport
The change in wind direction with altitude caused by the varying effect of surface friction.
A large group of amoeboid protists with reticulating pseudopods—fine strands of cytoplasm that branch and merge to form a dynamic net. They typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in structure.
a circular or spiral motion, especially a circular ocean current
marine snow
The tiny leftovers of animals, plants, and non-living matter in the ocean’s sun-suffused upper zones. Among these particles are chains of single-celled plants called diatoms, shreds of zooplankters’ mucous food traps, soot, fecal pellets, dust motes, radioactive fallout, sand grains, pollen, and pollutants.

Microorganisms also live inside and on top of these odd-shaped flakes.

North Atlantic Oscillation (NAO)
A major disturbance of the atmospheric circulation and climate of the North Atlantic-European region, linked to a waxing and waning of the dominant middle-latitude westerly wind flow during winter.The NAO Index is based on the pressure difference between various stations to the north (Iceland) and south (Azores) of the middle latitude westerly flow. It is, therefore, a measure of the strength of these winds.
Pacific Decadal Oscillation (PDO)
A pattern of Pacific climate variability that shifts phases on at least inter-decadal time scale, usually about 20 to 30 years. The PDO is detected as warm or cool surface waters in the Pacific Ocean, north of lat. 20° N. During a “warm” or “positive” phase, the west Pacific becomes cool and part of the eastern ocean warms; during a “cool” or “negative” phase, the opposite pattern occurs.

Microscopic plants that live in the water column of oceans, seas, and bodies of fresh water and are the foundation of the marine food chain.
specific heat capacity
The amount of heat, measured in calories, required to raise the temperature of one gram of a substance by one Celsius degree.
A layer within a body of water or air where the temperature changes rapidly with depth.The thermocline varies with latitude and season: it is permanent in the tropics, variable in the temperate climates (strongest during the summer), and weak to nonexistent in the polar regions, where the water column is cold from the surface to the bottom.

thermohaline circulation
The global density-driven circulation of the oceans.
An oceanographic phenomenon that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-deplete surface water.
Walker circulation
An atmospheric circulation of air at the equatorial Pacific Ocean, responsible for creating ocean upwelling off the coasts of Peru and Ecuador. This brings nutrient-rich cold water to the surface, increasing fishing stocks.
Microscopic animals that live in the water column of oceans, seas, and bodies of fresh water.

The smallest zooplankton can be characterized as recyclers of water-column nutrients and often are closely tied to measures of nutrient enrichment. Larger zooplankton are important food for forage fish species and larval stages of all fish.

The increase in concentration of a chemical in organisms that reside in environments contaminated with low concentrations of various organic compounds.
Broad regional areas characterized by a distinctive climate, soil type, and biological community.

carrying capacity
The number of individuals an environment can support without significant negative impacts to the given organism and its environment.
carbon dioxide fertilization
 Increased plant growth due to a higher carbon dioxide concentration.
Simultaneous evolution of two or more species of organisms that interact in significant ways.
competitive exclusion principle
The hypothesis stating that when organisms of different species compete for the same resources in the same habitat, one species will commonly be more successful in this competition and exclude the second from the habitat.
 Process of reducing nitrate and nitrite, highly oxidised forms of nitrogen available for consumption by many groups of organisms, into gaseous nitrogen, which is far less accessible to life forms but makes up the bulk of our atmosphere.
fundamental niche
The full range of environmental conditions (biological and physical) under which an organism can exist.
gross primary productivity (GPP)
The rate at which an ecosystem accumulates biomass, including the energy it uses for the process of respiration.
Those species that invest more heavily in fewer offspring, each of which has a better chance of surviving to adulthood.

keystone species
A single kind of organism or a small collection of different kinds of organisms that occupy a vital ecological niche in a given location.
latitudinal biodiversity gradient
The increase in species richness or biodiversity that occurs from the poles to the tropics, often referred to as the latitudinal gradient in species diversity.
life history strategy
An organism’s allocation of energy throughout its lifetime among three competing goals: growing, surviving, and reproducing.

Evolving to appear similar to another successful species or to the environment in order to dupe predators into avoiding the mimic, or dupe prey into approaching the mimic.
Refers to an interaction between two or more distinct biological species in which members benefit from the association. Describes both symbiotic mutualism (a relationship requiring an intimate association of species in which none can carry out the same functions alone) and nonsymbiotic mutualism (a relationship between organisms that is of benefit but is not obligatory: that is, the organisms are capable of independent existence).
net primary productivity (NPP)
The rate at which new biomass accrues in an ecosystem.
niche partitioning
The process by which natural selection drives competing species into different patterns of resource use or different niches.

Coexistence is obtained through the differentiation of their realized ecological niches.

nitrogen fixing
The conversion of nitrogen in the atmosphere (N2) to a reduced form (e.g., amino groups of amino acids) that can be used as a nitrogen source by organisms.
primary producers
;Organisms that produce organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis. Primary production is distinguished as either net or gross. All life on earth is directly or indirectly reliant on primary production.

realized niche
;The ecological role that an organism plays when constrained by the presence of other competing species in its environment
Species with a reproductive strategy to produce many offspring, each of whom is, comparatively, less likely to survive to adulthood.
species richness
A type of approach to assessing biodiversity that examines the distribution of all resident terrestrial vertebrates: amphibians, reptiles, birds, and mammals.
A fundamental concept in ecology that refers to the more or less predictable and orderly changes in the composition or structure of an ecological community.
trophic cascades
Occur when predators in a food chain suppress the abundance of their prey, thereby releasing the next lower trophic level from predation (or herbivory if the intermediate trophic level is an herbivore).

Trophic cascades may also be important for understanding the effects of removing top predators from food webs, as humans have done in many places through hunting and fishing activities.

trophic level
a feeding level within a food web