extinction rate. This rapid increase in the extinction rate is being referred to as
The Sixth Mass Extinction. The sixth differs from the previous five in that they
were all natural occurrences. The current extinction rates are driven by increased
Session Ten: Geology
Earth is approximately 4.5 billion years old. Scientists believe that life originated
on Earth 3.8 billion years ago. These vast amounts of time are best measured
with the geologic time scale. The geologic time scale relates ge
Session Eight: Populations
A population is a group of one species that live in the same area and can
successfully interbreed. Several terms can be used when describing individuals
within a population.
Generalists are organisms that have very broad niches.
Session Three: Soil, Agriculture, and Food Production
Throughout most of our relatively short human history, we have survived as
hunter-gatherers. Approximately 10,00012,000 years ago, we began to
practice early forms of agriculture. This was the beginnin
Session Six: Biomes
Aquatic biomes are defined based on the presence or absence of salt.
Freshwater biomes have a salt concentration of less than 1 %; whereas marine
biomes have a salt concentration greater than 3 %.
Oceans cover more than 7
Session Five: BioGeoChemical Cycles
Water is constantly moving through the biosphere through evaporation,
condensation, transpiration and precipitation. These processes are
collectively known as the hydrologic or water cycle. When disturbance is kept
Session Two: APES Environmental History and Other Important Stuff!
Environmental history is rarely tested directly on the exam. However, there are
some important people, dates, etc. that you should know about. It is also
important to have some historical
Session Four: Air Quality and The Atmosphere
Our atmosphere is a layer of gases that surrounds the planet. These gases are
held close to the planet by gravity. For the purpose of the AP exam, you should
be concerned with the following layers of the atmosp
Session Seven: Ecology
Ecology is the study of relationships formed between the biotic (living) and
abiotic (non-living) factors found in nature. Environmental Science studies these
relationships and interactions at several different levels. Environmental
Session One: The Exam
Before you begin to cram for the exam, lets look the beast in the eye to see what
youre really up against. Here well break down the multiple choice and free
response portions of the exam, and begin to develop some test day strategies