C4.2 SL / HL Flashcards
Mesocosms
any outdoor experimental system that examines the natural environment under controlled conditions
Closed system
one that cannot transfer energy to its surroundings. Biological organisms areopen systems
biosphere
the region of the earth that encompasses all living organisms: plants, animals and bacteria
Open system
one in which energy can be transferred between the system and its surroundings
Laws of the conservation of matter / energy
the magnitude of properties within a chemical system, such as mass, energy, or charge, remain unchanged during a chemical reaction. These properties may be exchanged between components of the system; however, the total amount in the system does not increase or decrease
Laws of thermodynamics
the First Law of Thermodynamics states that total energy in a closed system is neither lost nor gained — it is only transformed. TheSecond Law of Thermodynamicsstates that entropy constantly increases in a closed system
Photons
a quantum of radiant energy with a visible wavelength. It is anelementary particlethat is its own antiparticle. It is a discrete concentration of energy
Producers
organisms that make their own food; they are also known as autotrophs
aphotic zone
the portion of a lake or ocean where there is little or no sunlight
chemoautotrophs
microorganisms that use inorganic chemicals as their energy source and convert them into organic compounds. These microorganisms are able to make what they need to supply themselves with nourishment and energy
geothermal pools
occurs when groundwater is geothermally heated by the earth’s crust
hydrothermal vents
the result of seawater percolating down through fissures in the ocean crust in the vicinity of spreading centers or subduction zones
Food chain
a linear sequence of organisms through which nutrients and energy pass as one organism eats another
Food web
a complex network of interconnecting and overlapping food chains showing feeding relationships within a community
excretion
the process of removing wastes and excess water from the body
decomposers
organisms that break down dead or decaying organisms
Detritivores
organisms that break-down and feed on dead and decaying organic materia
saprotrophs
a type ofdecomposerthat feeds exclusively on dead and decaying plant matter
Humus
a substance made from dead leaves and plants, that put into the ground to help plants grow. Humus is partially decayed organic matter
topsoil
the upper layer of soil. It has the highest concentration of organic matter and microorganisms and is where most of the Earth’s biological soil activity occurs
Photoautotrophs
organisms that can utilize light energy from sunlight and elements (such as carbon) from inorganic compounds to produce organic materials needed to sustain their own metabolism
Carbon fixation
the conversion of atmospheric carbon dioxide into organic molecules by autotrophic organisms
Chemoautotrophs
microorganisms that use inorganic chemicals as their energy source and convert them into organic compounds
hydrogen sulfide
a chemical compound with the formula H2S. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs
hydrolysis
any chemical reaction in which a molecule of water breaks one or more chemical bonds
ATP
the principal molecule for storing and transferring energy in cells
spontaneous reaction
a reaction that proceeds on its own in a given set of conditions, without the external addition of energy.
iron-fixing bacteria
long thread-like bacteria that “feed” on iron and secrete slime. Unlike most bacteria, which feed on organic matter, iron bacteria fulfill their energy requirements by oxidizing ferrous iron into ferric iron
Heterotrophs
organisms that consume other organisms for energy
assimilated
the process of absorption of vitamins, minerals, and other chemicalsfrom food as part of the nutrition of an organism
cellular respiration
the process by which biological fuels are oxidized in the presence of an inorganic electron acceptor, such as oxygen
oxidation reactions
a process that occurs when atoms or groups of atoms lose electrons
Trophic level
any step in a nutritive series, or food chain, of an ecosystem
primary consumer
animals that eat plants as part of their diet or as their entire diet
Secondary consumer
The organisms that eat the primary consumersare called secondary consumers
Tertiary consumer
animals that eat other animals
Quaternary consumer
an animal that consumes at the very top of the food chain, after the primary consumer
top carnivore
carnivores occupying the top level of a food chain or a number pyramid
ecological pyramids
a graphical representation in the form of a pyramid showing the feeding relationship of groups of organisms
Pyramid of numbers
shows the total number of individual organisms at each level in the food chain of an ecosystem
Pyramid of biomass
the representation of total living biomass or organic matter present at different trophic levels in an ecosystem
Pyramid of energy
a model that shows theflow of energyfrom one trophic, or feeding, level to the next in an ecosystem
10% Rule
when energy is passed in an ecosystem from one trophic level to the next, only ten percent of the energy will be passed on
Biomass
biological material derived from living, or recently living organisms
primary production
the production of chemical energy in organic compounds by living organisms. The main source of this energy is sunlight but a minute fraction of primary production is driven by lithotrophic organisms using the chemical energy of inorganic molecules
Secondary production
the formation of living mass of a heterotrophic population or group of populations over some period of time
Atmosphere
a mixture of gases that surrounds the Earth
Lithosphere
the solid, outer part of Earth
Hydrosphere
the total amount of water on a planet
Source
any natural or artificial production site of carbon and/or any chemical compounds composed of carbon, such as carbon dioxide and methane
Sink
anything that absorbs more carbon from the atmosphere than it releases
Flux
the rate of exchange of carbon between the variouscarbon sinks/ reservoirs
methanogenic archaea
a unique group of strictly anaerobic microorganisms characterized by their ability, and dependence, to convert simple C1 and C2 compounds to methane for growth
Peat
surface organic layer of a soil that consists of partially decomposed organic matter, derived mostly from plant material, which has accumulated under conditions of waterlogging, oxygen deficiency, high acidity and nutrient deficiency
partial decomposition
incomplete decomposition of organic waste / dead matter
waterlogged soil
excess water in the root zone accompanied by anaerobic conditions
Fossilization
the process of an animal or plant becoming preserved in a hard, petrified form
combustion
a chemical reaction between substances, usually including oxygen and usually accompanied by the generation of heat and light in the form of flame
permafrost soil
permanently frozen layer on or under Earth’s surface. It consists of soil, gravel, and sand, usually bound together by ice.
Fossil fuel
compound mixtures made of fossilized plant and animal remnants from millions of years ago. The creation of fossil fuels—either oil, natural gas, or coal—from these fossils is determined by the type of fossil, the amount of heat, and the amount of pressure
Keeling Curve
a graph that represents the concentration of carbon dioxide (CO2) in Earth’s atmosphere since 1958
