1. Christie, Reyna, Alexandra, Karina, Reyna, Pia
Biology Topic 5 Outline
5.1) Communities and Ecosystems:
Species- a group of organisms that can interbreed and produce fertile offspring
Population- a group of organisms of the same species who live in the same area at the
same time
Community- a group of organisms living and interacting with each other in a specific
area
Ecosystem- a community and its abiotic environment
Ecology- the study of relationships between living organisms and between organisms
and their environment
Autotroph- an organism that synthesizes its organic molecules from simple inorganic
substances
Heterotrophy- an organism that obtains organic molecules from other organisms
Consumer- an organism that ingests other organic matter that is living or recently killed
Detritivore- an organism that ingests dead organic matter
Saprotroph- an organism that liven on or in dead organing matter, secreting digestive
enzymes into and absorbing the products of digestion
Food chain- a sequence showing the feeding relationships and energy flow between
species
Food web- the feeding relationships between species including the possibility of one
species having more than one trophic level
Trophic level- the position on the food chain according to how many energy-transfer
steps is required to reach that level
Light- initial source of energy for almost all communities
Energy flow- energy losses between trophic levels such as heatloss through cell
respiration, bone marrow and material not assimilated
Pyramid of energy- the shape shows the flow of energy from trophic level to trophic
level in a community.
Enters and leaves- energy does this in an ecosystem
Is recycled- nutrients do this in an ecosystem
Recycle nutrients- done by saprotrophic baceria and fungi
5.2) The Greenhouse Effect
Greenhouse effect- warming of the Earth due to the insulating effect of gases in the
atmosphere, such as carbon dioxide (CO2) and methane (ch4) and water vapor
Clean air act of 1970- A law that Set air-quality standards and tough emissions
guidelines for car manufacturers
Baghouse- a system of large filters that physically removes particulate matter from
incinerator emissions
Scrubbers- Equipment designed to extract or "scrub" sulfur gases before they escape
into the atmosphere

2. Catalytic converters- Causes the exhaust gases (carbon monoxide, hydrocarbons, &
nitrogen oxides) to react and in doing so forming less harmful carbon dioxide and water
Heavy smog incident- ollution trapped near the earth's surface donoran PA, smog hits
the town because the factory creates so much pullution it creates a thermal inversion
Ozone Layer- a layer in the stratosphere (at approximately 20 miles) that contains a
concentration of ozone sufficient to block most ultraviolet radiation from the sun
Thermal inversion- The temperature inversion in which warm air traps cold air and
pollutants near the earth
Photochemical smog- a brownish haze that is a mixture of ozone and other chemicals,
formed when pollutants react with each other in the presence of sunlight. sun
+no2+voc's= ozone (smog)
Evidence of global climate change- temp. increased 4-7 degrees. ice (glaciers) is breaking
apart
Voc's- volatile organic compounds, produced by paint fumes, vehicles and burning fuels
Reduction of global climate change- shorter showers, turn off lights when you leave the
room, solar panels (sun energy), build turbines (wind energy), drive less
Effects of global climate change- melting polar ice caps (polar bears dying), raising ocean
levels (wipe out costal towns and islands),
Carbon monoxide- an odorless very poisonous gas that is a product of incomplete
combustion of carbon/fossil fuesl. effects: interfers with the blood stability, dangerously
high concentration which causes death
Nitrogen oxide- formed when combustion (burning) temps. exceed 538c and nitrogen
and oxygen combine brownish haze to smog
Sulfur oxide- the compound made by combining sulfur (S) with oxygen (O) to form
SO₃burning coal
Particulate matter- tiny particles of liquid or solid matter construction/ agriculture, fires,
vehicles, and industrial process
Lead- a toxic metal
Tropospheric ozone- Man- made pollutant in the lower atmosphere, secondary air
pollutant, component of photochemical smog
Composition of air- 78%nitrogen, 21% oxygen, 9% argon, .04% carbon dioxide
5.3) Populations
Natality- The number of new membranes of the species due to reproduction
Mortality- The number of deaths
Immigration- Members arriving from other places
Emigration- Members leaving the population
Exponential Growth- Number of individuals increases at a faster and faster rate
Transitional Phase- The growth rate slows down considerably, population is still
increasing but at a slower and slower rate
Plateau Phase- The number of individuals has stabilized