Chapter 4 Flashcards
Organism
Any form of life.
Eukaryotic
Cell containing a nucleus, a region of genetic material surrounded by a membrane. Membranes also enclose several of the other internal parts found in a eukaryotic cell.
Prokaryotic
Cell that does not have a distinct nucleus. Other internal parts are not eclipsed by membranes.
Species
Group of organisms that resemble one another in appearance, behavior, chemical makeup and processes, and genetic structure. Organisms that reproduce sexually are classified as members of the same species only if they can actually or potentially interbreed with one another and produce fertile offspring.
Population
group of individual organisms of the same species living in a particular area.
Genetic diversity
Variability in the genetic makeup among individuals within a single species.
Habitat
Place or type of place where an organism or population of organisms lives.
Distribution/range
Area over which we can find a species
Community/biological community
Populations of all species living and interacting in an area at a particular time.
Ecosystem
Community of different species interacting with one another and with the chemical and physical factors making up its nonliving environment.
Biosphere
Zone of earth where life is found. It consist of parts of the atmosphere (the troposphere), hydrosphere (mostly surface water and groundwater), and the lithosphere (mostly soil and surface rocks and sediments on the bottoms of oceans and other bodies of water) where life is found.
Atmosphere
The whole mass of air surrounding the earth.
Troposphere
Innermost layer of the atmosphere. It contains about 75% of the mass of the earth’s air and extends about 17 kilometers (11 miles) above sea level.
Stratosphere
Second layer of the atmosphere, extending about 17-48 kilometers (11-30 miles) above the earth’s surface. It contains small amounts of gaseous ozone (O3) which filters out about 95% of the incoming harmful ultraviolet (UV) radiation emitted by the sun.
Hydrosphere
The earth’s liquid water (oceans, lakes, other bodies of surface water, and underground water), frozen water (polar ice caps, floating ice caps, and ice in soil, known as permafrost), and water vapor in the atmosphere.
Lithosphere
Outer shell of the earth, composed of the crust and the rigid, outermost part of the mantle outside the asthenosphere; material found in earth’s plates.
Biome
Terrestrial regions inhabited by certain types of life, especially vegetation. Examples are various types of deserts, grasslands, and forests.
Anaerobic respiration/fermentation
Form of cellular respiration in which some decomposers get the energy that they need through the breakdown of glucose (or other nutrients) in the absence of oxygen.
Species diversity
Number of different species (spices richness) and their relative abundances (species evenness) in a given area or community.
ecological diversity
The variety of forests, deserts, grasslands, oceans, streams, lakes, and other biological communities interacting with one another and with their nonliving environment.
functional diversity
Biological and chemical processes or functions such as energy flow and matter cycling needed for the survival of species and biological communities.
food web
Complex network of many interconnected food chains and feeding relationships.
biomass
Organic matter produced by plants and other photosynthetic producers; total dry weight of all living organisms that can be supported at each trophic level in a food chain or web; dry weight of all organic matter in plants and animals in a an ecosystem; plant materials and animal wastes used as fuel.
Gross primary productivity (GPP)
The rate at which an ecosystem’s producers capture and store a given amount of chemical energy as biomass in a given length of time.
Net primary productivity (NPP)
Rate at which all the plants in an ecosystem produce net useful chemical energy; equal to the difference between the rate at which the plants in an ecosystem produce useful chemical energy (gross primary productivity) and the rate at which they use some of that energy through cellular respiration.
Soil horizon
Horizontal zones that make up a particular mature soil. Each horizon has a distinct texture and composition that vary with different types of soils.
Soil profile
Cors-sectional view of the horizons in soil.
Infiltration
Downward movement of water through soil.
Leaching
Process in which various chemicals in upper ;ayers of soil are dissolved and carried to lower layers and, in some cases, to groundwater.
Evaporation
Conversion of a liquid into a gas.
Transpiration
Process in which water is absorbed by the root systems of plants, moves up through the plants, passes through pores (stomata) in their leaves or other parts, and evaporates into the atmosphere as water vapor.
Condensation
Conversion of water vapor into droplets of liquid water.
Precipitation
Water in the form of rain, sleet, hail, and snow that falls from the atmosphere onto the land and bodies of water.
percolation
Passage of a liquid through the spaces of a porous material such as soil.
runoff
Freshwater from precipitation and melting ice that flows on the earth’s surface into nearby streams, wetlands, and reservoirs.
condensation nuclei
Tiny particles on which droplets of water vapor can collect.
glaciers
fresh water returned to earth’s surface as precipitation becomes locked up in slowly moving flowing ice and snow.
surface runoff
Water flowing off the land into bodies of water.
aerobic respiration
Complex process that occurs in the cells of most living organisms, in which nutrient organic molecules such as glucose (C6H12O6) combine with oxygen (O2) and produce carbon dixoide (CO2), water (H2O), and energy.
fossil fuels
Products of parietal or complete decomposition of plants and animals that occur as crude oil, coal, natural gas, or heavy oils as a result of exposure to heat and pressure in the earth’s crust over millions of years.
nitrogen fixation
Conversion of atmospheric nitrogen gas into forms useful to plants by lightning, bacteria, and cyanobacteria; it is part of the nitrogen cycle.
nitrification
specialized aerobic bacteria convert most of ammonia in the soil to nitrite ions (NO2-), and nitrate ions (NO3-).
nitrite ions
(NO2-), which are toxic to plants.
ammonification
vast armies of specialized decomposer bacteria convert this detritus into simpler nitrogen-containing inorganic compounds such as ammonia and water-soluble salts containing ammonium ions.
denitrification
Nitrogen leaves the soil, other specialized anaerobic bacteria in water-logged soil and in the bottom sediments of lakes, oceans, swamps, and bogs convert NH3 and NH4+ back into nitrite and nitrate ions and then into nitrogen gas (N2) and nitrous oxide gas (N2O).
nitrate ions
(NO3-) Which are easily taken up by plants.
