APES AP EXAM STUDY GUIDE

First Law of Thermodynamics

energy is neither created nor destroyed, may be converted from one form to another.

Second Law of Thermodynamics

when energy is changed from one form to another, some useful energy is degraded into lower quality energy (usually heat).

Energy

the ability to do work. Units of energy: joules, calories, kilocalories, British thermal units (BTUs), Kilowatt-hours (kWh)

Power

the rate of doing work (work/time). Units of power: watts and kilowatts.

High quality energy

easily converted to useful work, organized and concentrated (ex: oil and nuclear)

Low quality energy

not easily converted to useful work, disorganized, dispersed (ex: heat).

Electromagnetic radiation

form of energy, travel as waves, e g radio waves, IR, visible light, UV, gamma rays.

Ionizing radiation

enough energy to knock electrons from atoms, forming ions, capable of damaging DNA. (Gamma, X rays, UV)

Radioactive decay

unstable radioisotopes decay releasing gamma rays, alpha and beta particles.

Half-life

time it takes for ½ of the mass of a radioisotope to decay. A radioisotope must be stored approximately 10 half lives before it has decayed to a safe level.

Nuclear fission

nuclei of isotopes are split apart into smaller nuclei; used in commercial nuclear reactors.

Nuclear fusion

2 isotopes of light elements are forced together at high temperatures. Happens on sun and stars, very difficult to accomplish on Earth, prohibitively expensive

Parts of hydrologic (Water) cycle

evaporation (transpiration = evaporation from plants), condensation, precipitation

Fate of precipitation

evaporation (transpiration), runoff or infiltration and percolation.

Aquifer

water saturated layer in ground, can yield a usable amount of water.

Water table

upper surface (top) of the aquifer (zone of saturation)

Overdraft

withdrawing water from a resource faster than it is replenished (discharge>recharge)

Recharge

water moving into a reservoir or aquifer

Cone of depression

lowering of water table around a pumping well.

Salt water intrusion

over pumping of groundwater near coast causes salt water to move into aquifer.

Ways to conserve water

agriculture- drip irrigation

industry - recycling

home use - fix leaks, use gray water, low flow fixtures

Distribution of water on Earth

97 % seawater, 3% freshwater (2% icecaps and glaciers, <1% in ground water, surface, organisms and atmosphere).

Major macronutrients

CHNOPS.

Micronutrients and trace elements

needed in small amounts.

Carbon

component of all organic molecules

Largest reservoir of carbon

(1) sedimentary rocks

(2) oceans.

Photosynthesis

Process by which plants convert CO2 to complex carbohydrates (C6H12O6), removes C from atmosphere.

Cellular respiration

organisms break down carbohydrates; releases energy, returns C to atmosphere.

Aerobic

requires oxygen

Processes that release C to the atmosphere

cellular respiration and decomposition, fires, burning fossil fuels, volcanoes.

Carbon-silicate cycle

slow, geological cycle: C in oceans used by marine organisms ends up in ocean sediments are subducted into Earth's crust, eventually returned through volcanic venting.

Nitrogen

component of proteins (amino acids) and nucleic acids.

Largest reservoir of nitrogen

atmosphere (78% N2). Producers cannot directly use nitrogen gas

Nitrogen fixation

N2 is converted to ammonia NH3. Bacteria do this (esp. Rhizobium living symbiotically with legumes)

Haber process

industrial N fixation, uses lots of fossil fuels

Nitrification

ammonia is converted to nitrite (NO2-) to nitrate (NO3-).

Assimilation

plants incorporate ammonia and nitrate ions into organic molecules (nucleic acids. amino acids).

Ammonification

Decomposers convert organic compounds into ammonia.

Denitrification

Specialized bacteria convert nitrogen compounds into N2 gas which is released into the atmosphere.

Phosphorous

component of nucleic acids, often a major limiting factor for plant growth.

Phosphorus cycle

more slowly: no gaseous phase, mostly found in rocks as PO4, released by weathering.

Too much P and N in aquatic ecosystems

from animal wastes, fertilizers, sewage can cause eutrophication.

Earth's age

4.5 billion years old.

1st cells appeared

approximately 3.5 billion years ago.

Most abundant elements in Earth's crust

O, Si, Al, Fe, Ca.

Most abundant in core

Fe and Ni

Plate tectonics

Earth's crust is broken into plates which move relative to each other; movement caused by convection currents dissipating internal heat. Internal heat is produced by radioactive decay and is residual from Earth's formation.

Volcanoes and earthquakes occur

at plate boundaries

Divergent plate boundaries

plates moving apart, resulting in sea floor spreading, new crust generated, ex: ocean ridges, rifts

Convergent plate boundaries

plates coming together, ocean - ocean or ocean- continental, results in subduction (one plate slides under other), causes volcanoes and trenches. Convergent continental plates produce mountains.

subduction

one plate slides under other

Transform boundaries

plates slide past each other causes earthquakes (ex: San Andreas Fault)

Rock cycle

relationship of rocks and rock formation processes.

igneous rocks come from

cooled molten rock

sedimentary rocks come from

weathering, erosion

metamorphic rocks come from

temperature, pressure

Minerals

are not renewable. Mineral deposits most abundant at plate boundaries.

Ore

concentration of mineral high enough to make it profitable to mine.

Mineral reserve

identified deposits, profitable to mine.

Surface mining: (strip mining)

cheaper, can remove more materials, less dangerous to miners. Problems: toxic runoff, acid drainage.

Soil texture

size of soil particles; sand, silt, clay (largestà smallest).

Humus

organic material in soil.

Leaching

removal of dissolved materials by water moving downwards.

Permeability

ability to transmit water (sandàhigh, clayàlow).

Porosity

amount of open space in soil (sand ishigh, clay islow).

Water holding capacity

how well soil can retain water (sand is low, clay is high)

Soil Salinization

in arid regions, irrigation water evaporates, leaving salts behind

Soil conservation techniques

contour plowing, crop rotation, conservation tillage, organic fertilizers, tree breaks, cover crops

Earth's atmosphere

composed of 78% N2, 21% O2, 0.9% argon, 0.035% CO2

Troposphere

0-17 km above Earth's surface, site of weather, organisms, contains most atmospheric water vapor. (temperature decreases with increasing altitude, pressure decreases)

Stratosphere

17-48 km above surface, contains ozone layer approximately 20-30 km above Earth's surface (12-18 miles) (temperature increases with increasing altitude, pressure decreases)

Earth's early atmosphere

CO2, methane, ammonia, no free O2,

Organisms altered atmosphere

increased O2 and N2, decreased CO2.

Weather

daily atmospheric conditions (temp and precip)

Climate

long term atmospheric conditions (averages and patterns of temperature and precipitation)

Global circulation patterns

caused by uneven heating of Earth's surface and Earth's rotation.

ENSO

El Nino Southern Oscillation; see-sawing of air pressure over Southern Pacific.

El Nino

In equatorial Pacific, trade winds weaken and warm surface water moves towards S America, suppressing upwelling of nutrient rich water along west coast of S America.

Effects of El Nino

disrupts food chains, alters precipitation patterns, fewer Atlantic hurricanes.

Greenhouse gases (GHG)

water vapor, CO2, methane CH4, CFC's; trap outgoing infrared radiation (heat), causing Earth to warm.

Effects of global warming

rising sea level, droughts, disruptions of ecosystems, shifts in vegetation.

Ocean acidification

increase in acidity (decrease in pH) of ocean water due to increased uptake of CO2 from atmosphere forming carbonic acid (H2CO3)

Carbon sequestration

the process of removing carbon from the atmosphere and storing it

Carbon credits

market trading of permits to emit carbon dioxide

Ozone depletion

break down of stratospheric ozone caused by: CFCs, methyl chloroform, carbon tetrachloride (CCl4), halon, methyl bromide

Effects of ozone depletion

increased UV (human health à increased skin cancer, cataracts, weakened immune systems ; environmental effects à decreased plant growth and marine productivity)

Biotic

living components of ecosystem

abiotic

non-living components of ecosystem

Producer/autotroph

organisms that can make their own food.

Consumer/heterotroph

organisms that cannot make their own food

Trophic levels

producers → primary consumers → secondary consumers → tertiary consumers.

Energy flow in food webs

Solar energy converted to chemical energy converted to heat. Plants convert 1% of sunlight received to chemical energy (biomass). Only 10% of energy from each trophic level is transferred to next trophic level. Reason: energy lost to heat (2nd Law), not all biomass is digested. Predators are especially inefficient due to energy used to catch prey.

Mutualism

symbiotic relationship where both organisms benefit.

Parasitism

relationship in which one partner obtains nutrients at the expense of the host.

Commensalisms

symbiotic relationship where partner benefits, the other is neither harmed nor benefited.

Competition

Organisms competing for the same resources.

Species

interbreeding group of organisms capable of producing fertile offspring