Mrs. Walker\’s Lessons

CHAPTER 7 NOTES“CLIMATE”SECTION 1: “WHAT IS CLIMATE?”Weater and climate differ because of time.Weather is the condition of the atmosphere at a particular time and place. For instance: What is the weather going to be like this week in Memphis?Climate is the average weather conditions in an area over a long period of time. The climate of Memphis is mild temperatures with lots of humidity.Climate is determined by 2 factors: temperature and precipitation.Climates differ for a number of reasons:1. Latitude2. Wind patterns3. Geography4. Ocean currentsLatitude:-latitude is the distance north or south, measured in degrees, from the equator.-The higher the latitude, the colder the climate. The North Pole is at 90 degrees North latitude and is one of the coldest places on Earth. The Equator is at 0 degrees and is one of the warmest.-The reason why there is a difference in temperature at the different latitude lines is because of the solar energy received from the sun at each latitude line. The sun’s rays hit the Earth at a 90 degree angle at the Equator causing this area to be the warmest. At the poles, the sun’s rays hit at a lesser angle creating less solar energy and a cooler climate.-Latitude also affects the seasons.-Land located on the equator or by the equator experience the same temperatures year round and the same amount of daylight year round because of the direct rays of the sun.- Because Earth is tilted on its axis at a 23.5 degree angle, the amount of solar energy an area recieves at a particular time is different from other regions on Earth.-During the winter months, the Southern Hemisphere has higher temperatures and longer days because it tilts toward the sun and recieves direct solar energy. The Northern Hemisphere has lower temperatures and shorter days because it tilts away from the sun.-During the summer months, the Northern Hemisphere is tilted toward the sun and receives direct solar energy and has longer days. The Southern Hemisphere has shorter days and colder temperatures because the solar energy is less since this area is tilted away from the sun.Prevailing Winds-These are winds that blow mainly in one direction and influence an area’s moisture and temperature.-Just like water, cold air sinks and warm air rises. As cold air sinks it will warm up. As it is heated, it is able to hold water vapor. As this warm air rises, it will cool down and lose its ability to hold water vapor and precipitation will occur. This is an ongoing cycle on Earth. This is why it is usually cooler after it rains.- Prevailing winds affect the amount of precipitation a region recieves. If the winds form from warm air, they will carry moisture. If they form from cool air, they will be dry. Memphis’ prevailing winds come from a warm area so we get more rain.-The amount of moisture a prevailing wind carries is also affected by whether it blows across land or water. Winds blowing over bodies of water absorb moisture. Winds that travel across land tend to by dry. Our winds usually cross the Mississippi River which creates moisture in our air.Geography-Mountatins can iinfluence an area’s climate. Mountains affect the temperature and precipitation of an area. Kilimanjaro, the tallest mountain in Africa has snow-covered peaks year-round even though it is located at 3 degrees south of the equator. This is due to elevation.-Elevation is the height of surface landforms above sea level. As the elevation increases, the atmosphere becomes less dense which decreases its ability to hold thermal energy and absorb it. Therefore, the temperatures are lower.-Mountatins also affect precipitation. Mountains can block the prevailing winds from blowing across a continent changing the amount of moisture the wind carries.Mountains force air to rise. The air cools as it rises and releases moisture as snow or rain. The land on this side(the windward side) is usually green and lush due to the amount of moisture. The other side of the mountain has dry air crossing over it. This air begins to sink and warm up by absorbing moisture. The dry conditions created by the sinking, warm air usually produce a desert. THis side is in a rain shadow.Ocean Currents-Surface currents which can be either warm or cold, are streamlike movements of water that occur at or near the surface of the ocean. As the surface currents travel they affect the temperature of the atmosphere above it. If the surface current is warm, the air above it will be warm. If the surface current is cool, the air above it will be cool.SECTION 2: CLIMATES OF THE WORLD3 Major climate zones of the Earth:1. Tropical2. Temperate3. Polar-Each zone has a temperature range that relates to its latitude. Each zone also has several climates due to the geography and the amount of precipitation in that area. Because of the different climates in each zone, the zones are broken down into biomes.-A biome is a large region characterized by a specific type of climate and the plants and animals that live there.The Earth’s Land Biomes are:1. Tundra2. Taiga3. Temperate forest4. Tropical rain forest5. Temperate grassland6. Tropical savanna7. Temperate desert8. Tropical desert9. Chaparral10. MountainsTROPICAL ZONE-Also known as the Tropics is the warm zone located around the equator. This zone extends from the Tropic of Cancer to the tropic of Capricorn. Because this zone recieves the most solar radiation, temperatures in this zone are usually hot, except at high elevations.-3 biomes in this zone: tropical rain forest, tropical desert, and tropical savanna.Tropical rain forest-Always warm and wet-Receive strong sunlight year round, causing little difference between seasons.-Contain the greatest number of plant and animal species of any biome.-The soil in the rain forest is very poor because of the rapid decay of animals and the nutrients are quickly absorbed in the soil and the plants take in all the nutrients. The nutrients not quickly absorbed are washed away by the heavy rains.Tropical Desert-Receives less than 25 cm or rainfall a year.-Driest place on Earth.-plants have adapted to surviving with little water.-They are divided into hot and cold deserts.-The majority of hot deserts are tropical deserts.-Caused by sinking cool air.-The temperature varies from hot daytime temperatures to cool nighttime temperatures.-Winters are usually mile.-The soil is poor in organic matter due to the dryness.-The dryness makes it hard to break down dead organic matter.Tropical Savannas-Sometimes called grasslands-Dominated by tall grasses, with trees scattered about.-Climate is usually very warm, with a dry season that lasts 4-8 months followed by short periods of rain.-Soils are generally nutrient poor, but grass fires, which are common during the dry season, leave the soils nutrient enriched.-Many plants use the fires to reproduce by sprouting from the roots after the upper part has been burned. The seeds of some depend on the fire to grow.TEMPERATE ZONE-the climate zone between teh Tropics and the polar zone.-Temperatures are moderate-Includes 4 biomes:1. Temperate forests2. Temperate grasslands3. Chaparral4. Temperate desertsTemperate Forests-Have very high amounts of rainfall and seasonal temperture differences.-Summers are usually warm and winters are usually cold.-The largest are deciduous which are trees that lose their leaves when the weather becomes cold. They tend to be broad-leaved.-The soils in decidiuous forests are usually fertile because of the high organic content given by the decaying leaves that drop every winter.-Evergreen forests consist of evergreen trees that keep their leaves year-round. They can be broad leaved or needle leaved trees. Pine trees are evergreens.-Mixed forests of evergreen and deciduous are found in humid climates such as Florida where winder temperatures rarely fall below freezing.Temperate Grasslands-Occur in regions that have too little rainfall for trees to grow.-Has warm summers and cold winters.-Also known as the prairies of North America and the steppes in Eurasia or the veldt in Africa and the pampas in South America.-Grasses are the most common type of vegetation found.-Have the most fertile soil of all the biomes so this biome is usually plowed and used for croplands.Chaparrals-Have cool, wet winters and hot, dry summers.-Vegetation is mainly evergreen shrubs, which are short, woody plnats with thick waxy leaves. These leaves are adaptations that help prevent water loss in dry conditions.-The shrubs grow in rocky nutrient-poor soil.-This vegetation has also adapted to fires.Temperate Deserts-Cold Desert-Receive less than 25 cm of rainfall a year.-Very hot in the daytime, but they tend to be very cold at night.-The temperatures sometimes drop below freezing.-This large change in temperature is due to low humidity and cloudless skies.-These conditions allow for a large amount of energy to reach the Earth’s surface during the day , but release it all at night.-Receive light snow during the winter.-Usually located inland or on the rain-shadow side of a mountain range.

CHAPTER 12 NOTES

Energy: the ability to do work.

Work: what you are doing.

You need energy to do work.  With no energy, work cannot be done.  Imagine when you are tired.  It is very difficult to do work whether it is physical or mental.  In order to gain some energy you need to eat something healthy or get some sleep.  It’s like recharging your own personal battery.

Potential energy vs. kinetic energy

Potential energy is energy stored based on the objects mass and/or position. 

Kinetic energy is energy of motion.

Mechanical energy is the total amount of energy of an object whether it is in motion or at rest.  Mechanical energy can be all potential, all kinetic, or some of both.

You can increase the potential of something by changing its position or adding mass.  This in turn will give the object more kinetic energy.

As an object moves its energy transfers from potential to kinetic.  The potential an object starts with will never be gained again unless you add another force to it.  For example on a rollercoaster.  In order to get the car to its greatest potential, a motor pulls the car to the top of the biggest hill.  The car will never reach the height of the first hill because its energy is being transferred to kinetic as it goes through the rest of its hills and loops.  You would need to push the car or have another motor pull the car back to more potential.  Some of the energy is transferred to heat due to friction, the opposing force of motion between two surfaces that are touching.  In this case it is the wheels and the track.  You can increase the potential of this rollercoaster by making the first hill higher or increase the mass of the car. 

Law of conservation of energy:  energy can be neither created nor destroyed.  It can only be transferred.  As it transfers, the total amount will always be the same as long as it is in a closed system (well-defined group of objects that transfers energy between one another).

All energy involves either motion or position.  They types of energy are:

1. Thermal: the total energy of the particles that make up an object.  The energy will be more if the temperature is higher because the particles that make up the object will be moving faster.  The heat given off from the movement of particles is what will be transferred to other objects.  (See the Laws of Thermodynamics below for more information on heat transfer)
2. Chemical: energy of a compound that changes as its atoms are rearranged to form new compounds.  This is a form of potential energy.  If you have more atoms bonded together, the amount of chemical energy will be more.  Examples: food, batteries, plants undergoing photosynthesis.
3. Electrical: energy of moving electrons. 
4. Sound: an object’s vibrations cause air particles to vibrate .
5. Light: vibrations of electrically charge particles.  Air particles do not vibrate with light energy.  Light energy can travel through a vacuum.
6. Nuclear: energy associated with changes in the nucleus of an atom.  This can occur during fusion (two nuclei fuse or join together) or during fission (one nucleus splits apart).  Examples: The sun uses nuclear fusion in the core to give off its energy and nuclear power plants use nuclear fission with uranium to create large amounts of energy.

Energy transfers from one form to the other.  When there is a transfer, the amount of energy should remain the same or close to the same.  Whenever there is energy, some is always transferred to heat which is never gained back.

Laws of Thermodynamics (flow of heat)

Zeroth Law: If two things have the same temperature (thermal equilibrium), no heat will flow between them.

First Law: Energy is always conserved (always adds up) throughout the universe. 

Second Law: Whenever we use energy, some of it becomes heat.

This law has taken away the dreams of many who believed that there could be a perpetual motion machine.  This is a machine that would put out exactly as much energy as it takes in.  So it would always move.  But, because some is transferred to thermal energy it will always need more.  Bummer!

Third Law: At absolute zero, all motion stops, but we can never quite get there.  (look on page 392 in your book)

Energy conversions are a change from one form of energy to another. 

Think about the pendulum we hung from the ceiling.  If I raised the ball higher, I gave it more potential.  As I released the ball, the pendulum swung away from me changed into kinetic energy.  When it reached its highest peak again it went back to potential.  This continued until the transfer slowed down the pendulum because some of the energy transferred heat to the air particles around it and to the string holding the ball.

Green plants use chlorophyll and light energy from the sun to produce the chemical energy in the food you eat.  This energy is then transferred into kinetic energy when we do work and also thermal energy in order to maintain our body temperature.

An alarm clock uses electrical energy to change into light and sound energy. 

A battery uses chemical energy to change into electrical energy.

A light bulb uses electrical energy to change into light and thermal energy.

A blender uses electrical energy to change into kinetic energy and sound energy.

ENERGY RESOURCES:

-       a natural resource that can be converted by humans into other forms of energy in order to do useful work.

We are constantly trying to find other sources in order to replace those we run out of.

Nonerenewable resources cannot be replaced after they are used or can be replaces only over thousands or millions of years. 

Example: Fossil fuels, energy resources that formed from the buried remains of plants an animals that lived millions of years ago.  These are coal, petroleum, and natural gas. 

Most of our coal use is for electrical power.  Petroleum is mostly used for gasoline, kerosene, and wax.  Natural gas is used in our homes for the stove and heating systems.

Nuclear energy is considered a use of nonrenewable resources because our supply of uranium is limited. 

Renewable resources can be used and replaced in nature over a relatively short period of time.  We use solar energy for power, energy from water, energy from wind, energy from within the Earth’s crust, and from plants or other organic matter called biomass. 

All types of resources have their good and bad.  Look on page 351 for more information.

CHAPTER 9 NOTES“A Family of Planets”Section 1: “The Nine Planets”- Galileo was the first one to study the planets using a telescope. Galileo discovered Jupiter’s four largest moons due to the telescope.- Scientists measure the distance in space by using astronomical units or the distance between Earth and the Sun.- Scientists also use the distance light travels to measure distance in space. Light travels at about 300,000 km per second in space. This means that in 1 second light travels 300,000 km or 7.5 times around Earth.- In one minute, light travles almost 18,000,000 km or one light-minute.-It takes light 8.3 minutes to reach Earth. The distance for Earth to the sun is 8.3 light-minutes.-Distances in the solar system are measured in light-minutes, and light-hours.-Distances between the stars is measured in light-years.INNER PLANETS:1. A.K.A. Terrestrial planets because they are small, dense, and rocky.2. They are spaced close together.3. The planets are:- Mercury– Venus- Earth- MarsOUTER PLANETS:1. A.K.A. gas giants except for Pluto because they are large planets that don’t have any known solid surfaces.2. They are spaced out in the solar system.3. The planets are:- Jupiter- Saturn- Uranus- Neptune- PlutoPlanet Comparisons(Surface gravity is pull of gravity from a surface. The smaller the planet, the less the pull of gravity there is)(Rotation is the spin of the object in space)(Period of Rotation is the amount of time it takes for an object to rotate once)(Orbit is the pathway an object takes as it revolves around another object in space)(Revolution is the motion of the body as it orbits another body in space)(Period of revolution is the time it takes for an object to revolve around the sun once)*MERCURY:-The days on Mercury are equal to 59 Earth Days. This is because Mercury spins on its axis much more slowly than Earth.-Every 88 Earth days, Mercury completes one revolution around the sun.VENUS:- Similar to Earth (a.k.a. Earth’s twin)- Earth and Venus are about the same size, mass, and density.- Sun rises in the west and sets in the East- Venus rotates in the opposite direction of Earth.- Venus rotates in a retrograde rotation or clockwise direction as appeared from the Northern pole of the planet.- Earth rotates in a prograde rotation because it spins clockwise when viewed from the North pole.- Densest terrestrial planet- Consists mostly of Carbon Dioxide, but also some of the most corrosive acids known.- Surface temperature is so high on Venus due to the greenhouse effect and the Carbon Dioxide. The temperature can reach 464 degrees C.- Hottest surface of any planet- Venus has an active surface like Earth. Figure 6 shows massive lava flows on Venus.EARTH:- Also called “An oasis in space”- The temperatures are warm enough to prevent water from freezing and cool enough to prevent boiling.- Water was the key to life forming and it is important for survival of living things.- We study Earth from space to see the impact humans have on the environment and how weather, climate, and pollution interact.MARS:- Called the red planet- Most studied planet in the solar system.- Temperature is very cold.- Pressure is very low so we would have trouble breathing there.- Water on Mars is frozen and dry river beds remain from where there once was water.-Mars is very rocky and has a volcanic system ranging 8,000 km across the surface.OUTER PLANETS- called the Gas Giants because they are made of gas.-Jupiter, Saturn, Uranus, and Neptune.-Pluto is icy so it is not in this group.- All gas giants have rings.JUPITER:- Called a Giant-made of Hydrogen and Helium mainly and the outer atmosphere is made of layerd clouds of water, methane, and ammonia.- the beautiful colors of Jupiter is due to the amounts of organic compounds.- The Great Red Spot is a long-lasting storm system which has a diameter of about one and a half times that of Earth.- the pressure changes on Jupiter change the liquid Hydrogen into a metallic liquid state.- Jupiter radiates much more energy into space than it gets from the sun because energy is continuously transferred from the interior to the exterior.SATURN:- 2nd largest planet- Made mostly of Hydrogen and Helium, with methane, ammonia, and ethane in the upper atmosphere.- Saturn gives off a lot more energy than received just like Jupiter. Scientists believe this is due to the helium raining out of the atmosphere and sinking to the core. In other words, Saturn is still forming.-Saturn has the largest rings.-The rings are made of icy particles that range in size from a few centimeters to several meters across.URANUS:- called a small giant- discovered by William Herschel in 1781.- atmosphere is made up of hydrogen and methane gase which absorbs the red part of sunlight strongly.-Has similar density to Saturn and Jupiter so it suggests lower percentages of light elements and more water in the interior.-Uranus is tipped over on its side-its axis of rotation is tilted almost 90 degrees and lies almost inteh plane of its orbit. So it lies parallel to the orbit instead of perpendicular. For part of a year on Uranus, one pole points toward to the sun while the other is in complete darkness. Scientists believe that Uranus was hit by a massive object causing it to tilt.NEPTUNE:- called the Blue World- causes Uranus to move off its predictable path because its pull of gravity.- Neptune’s atmosphere is like Uranus except it contains a belt of clouds that are more visible.-Had a great dark spot like Jupiter’s red spot.-Its interior releases energy to the outer layers, which helps the warm gases rise and the cool gases sink. This sets up the wind patterns of the atmospher and creates the belts of clouds.PLUTO:- The farthest planet from the sun and the smallest.- Pluto’s moon is more than half its size. The largest satellite in the solar system as far as its relationship to the planet.- Pluto is composed of rock and ice.- Its atmosphere is of methane and is thin.- Pluto is covered by nitrogen ice and its moon, Charon, is covered by water ice.SECTION 2: MOONS (pg. 243)-Satellites are natural or artificial bodies that revolve around larger bodies like planets.- Mercury and Venus have no moons.EARTH’S MOON: LUNA-Luna’s density is much less than Earth’s, which means it has a lower percentage of heavy elements than Earth.- Samples show that the moon’s composition is similar to Earth’s mantle. The samples also show that the moon is 4.6 billion years old. This also implies that the solar system is the same age.- Surfaces with no atmosphere show all records of impacts had with other objects.In other words you can look at the surface of the moon is see its history.- Scientists are able to count the craters on Luna and use that number estimate how old other satellites are.-The theory of the moon’s formation as of now is that a mars-sized object collided with Earth while the Earth was still forming. This collision was so violent that part of Earth’s mantle was blasted into orbit around Earth.Phases of the Moon:- The changing appearance of the moon is due to its changing position in relation to the Earth and sun. As the moon revolves around Earth, the amount of sunlight on the side of the moon that faces Earth changes.-Phases are the different appearances of the moon due to its changing position.-A waxing moon means that the sunlit fraction we see from Earth is getting larger.(think of waxing on more light)-A waning moon means that the sunlit fraction is getting smaller.-Remember that half of the moon is always in sunlight, just like Earth always has half in sunlight.-Because the moon has the same period of rotation and period of revolution, we always see the same side of the moon from Earth.Phase order:New MoonWaxing crescentFirst quarterWaxing gibbousFull moonWaning gibbousLast quarterWaning crescentEclipse (black out)- An eclipse occurs when the shadow of one celestial falls on another.-A lunar(Luna-our moon) eclipse happens when the Earth comes between the sun and the moon, and the shadow of the Earth falls on the moon.-A solar eclipse happens when the moon comes between the Earth and the sun, and the shadow of the moon falls on part of Earth.OTHER MOONS:-All of the gas giants have multiple moons and some are still being discovered.-Some moons have very elongated or elliptical orbits and some revolve around their planet backward. Many of the small moons may be captured asteroids.MARS:-2 moons (Phobos and Deimos)-The surface is similar to asteroids.JUPITER:-28 or more moons-4 largest: Ganymede, Callisto, Io, and Europa.-Ganymede is the largest and larger than Mercury. The smaller ones are likely to be asteroids.-Io is bizarre because it experiences a tug-of-war between Jupiter and Europa. This tugging stretches Io and causes it to heat up, which makes it the most volcanically active body in the solar system.-Europa pictures support the idea of liquid water lieing beneath the moon’s icy surface.SATURN:-30 known moons-Most of the moons are small bodies made mostly of water ice with some rocky material-Titan is the largest satellite and its atmosphere is similar to Earth’s before life began.URANUS:-21 moons-the 4 largest are made of ice and rock and heavily cratered.-Miranda is the smallest. Its surface is smooth, cratered plains as well as regions with grooves and cliffs up to 20 km high.NEPTUNE:-8 moons-Triton is the largest and revolves in retrograde or backwards orbit. This suggests it may hhave been captured by Neptune’s gravity. Triton has a very thin atmosphere made mostly of nitrogen gas. The surface consists mainly of frozen nitrogen and methane, The surface is active and shoots nitrogen gas into the atmosphere.-The other 7 are rocky worlds.PLUTO:-One moon-Charon-Charon’s period of revolution is the same as Pluto’s period of rotation-6.4 days. This means one side of Pluto always faces Charon. This would be like Earth’s moon never moving. It would stay in the same spot.-Charon’s orbit around Pluto is tilted so sometimes, Pluto is eclipsed by Charon. This happens once every 120 years.SECTION 3:SMall Bodies in the Solar SystemComets:-Comets are small bodies of ice, rock, and cosmic dust loosely packed together.-Also called dirty snowballs.-They come from the cold outer solar system.Comet tails-When a comet passes close enough to the sun, solar radiation heats the water ice so that the comet gives off gas and dust in the form of a long tail.-A comet can have 2 tails-an ion tail and a dust tail.-The ion tail is made of electrically charged particles called ions.-The solid center of a comet is the nucleus.Comet orbits-Highly elliptical or very elongated.-The comet’s ion tail always points directly away from the sun because it is blown away from the sun by solar wind.Comet origins:-Scientists think comets come from the Oort Cloud which surrounds the solar system.-When gravity of passing planets or stars disturb the cloud, comets can be pulled in toward the sun.-Kuiper Belt also consists of comets. It is located outside the orbit of Neptune.ASTEROIDS-Asteroids are small, rocky bodies in orbit around the sun.-Asteroid belt is the region between Mars and Jupiter where most asteroids orbit.-Asteroids are thought to be leftovers form the formation of the solar system,METEROIDS-A meteoroid is a small, rocky body orbiting the sunl. They are similar to asteroids, but much smaller. Most probably came from asteroids.-A meteorite is when a meteoroid enters Earth’s atmosphere and strikes the ground. When this happens the meteoroid is traveling so fast that it heats up and melts. As it burns up it glows red hot and gives off an enormous amount of light. We see this as spectacular streak of light.-A meteor is the bright light caused by the meteoroid or comet dust burning up in the atmosphere.Meteor showers occur when Earth passes through the dusty debris leftg behind in the orbit of a comet.Impacts:Planets and moons that have no atmosphere have more impact craters.Earth’s moon has more impact craters than Earth because it has no atmosphere or tectonic activity. Earth’s atmosphere serves as a shield and any object that reaches its surface burn up. The craters Earth once had have been weathered, eroded, or erased by tectonic activity.

CHAPTER 5: THE ROCK AND FOSSIL RECORD

SECTION 1: (PG. 112)
- geology is the study of Earth’s history.
- James Hutton published “Theory of the Earth” which spoke of unifromitarianism. This means that the same geologic processes occuring today occurred long ago. “The present is the key to the past.”
- Catastrophism is all geologic change occurs suddenly. By catastrophes.
- Scientists believed catastrophism because they thought Earth was only thousands of years old. This was not enough time for uniformitarianism to occur.
- Charles Lyell published “Principles of Geology” (3 volumes) which reintroduced uniformitarianism. He challenged catastrophism successfully.
-Result: Most change is gradual and uniform, but catastrophes do occur.

SECTION 2: (PG. 115)
- “Relative Dating: Which came first?”
- Relative Dating is determining whether an object or event is older or younger than other objects or events.
- Imagine if you never cleaned out your locker. You kept throwing items in there until it was packed all the way to the top. The most recent items would be on top and the oldest on bottom. Just like rock layers! (Superposition)
- Superposition is younger rocks lie above older rocks in undisturbed sequences. “ Younger over older.”
- Some layers are disturbed by forces within the Earth. Older layers can be pushed above younger ones. The geologists look at the geologic column for help.
- Geologic column is the ideal sequence of rock layers that contains known fossils and rock formations on Earth arranged from oldest to youngest.
-Read page 117.
- Fault, intrusion, folding, tilting-disruptions in the rock layers
-Sometimes rock layers can be missing which creates gaps in rock layer sequences called uncomformities. (represents a missing part)-or missing time. Nondeposition and erosion can cause this.
- Most are formed by both nondeposition and erosion.
- 3 categories of uncomformities: discomformities, nonconformities, and angular unoconformities.

SECTION 3: ABSOLUTE DATING: A MEASURE OF TIME (PG. 120)
- Absolute dating is the process of establishing the age of an object, such as a fossil or rock layer, by determining the number of years it has existed.
WAYS TO DETERMINE ABSOLUTE DATING OF FOSSILS AND ROCKS:
1. Analyze radioactive isotopes (most often used )
- isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. Most are stable, but some are unstable, which means they change forms(radioactive).
- Radioactive Decay: process of radioactive isotopes breaking down into stable
isotopes of other elements.
- Scientists use the relative amounts of stable and unstable isotopes present to
determine the age.
- Radiometric Dating: determining the absolute age of a sample based on the
ratio of parent material to daughter material.
- parent material is the original isotope. The decayed parent materials becomes
daughter material. The amount of parent material left aids in the accurate aging
of the object because scientists know how quick or slow isotopes decay into
another.
- Half-life: the amount of time it takes for one-half of radioactive sample to decay.
- the older the rock the more daughter material there is.
Types of Radiometric Dating
-Uranium-Lead Method is used for rocks more than 10 million years old. Its half-life is 4.5 billion years. Uranium decays into lead.
- Potassium -Argon Method- Potassium has a half-life of 1.3 billion years. It decays to Argon and Calcium. Argon is the daughter material. This method is used to date rocks older than 100,000 years.
- Carbon-14 Method- Carbon is found in 3 forms:
1. Carbon-12
2. Carbon-13
3. Carbon-14
They combine with oxygen to form carbon dioxide used in photosynthesis. As long as plants are alive, a constant carbon-14 to carbon-12 is taken in. Once they die, no new carbon is taken in. Carbon-14 begins to decrease as the plant or animal decays. Half-life is 5,730 years. Used for the last 50,000 years.

SECTION 4: LOOKING AT FOSSILS (PG. 124)
- fossil: any naturally preserved evidence of life.
- preserved organisms are the easiest fossils to identify.
-Fossils in rocks- hard part of the organism’s body is buried under sediment and preserved.
- Mineral Replacement:
permineralization is the process which minerals fill in pore spaces of an organism’s
tissues.
petrification is the organism’s tissues are completely replaced by minerals.
-Fossils in Amber: organism gets stuck in sap and covered by more sap. It then hardens.
-Mummification: organisms die in dry places and they dry out so quickly that there is not time for their soft parts to decay.
-Frozen fossils: frozen specimens due to freezing.
-Fossils in Tar: natural tar pits.

OTHER FOSSILS
- Trace fossils are any naturally preserved evidence of an animal’s activity (tracks)
Tracks are filled with sediment and hardened
- Burrows are forms of trace fossils. An animals shelter can be filled with sediment.
-Coporlites (“dung stone” Greek word) preserved feces from animals.
-Molds an Casts
Mold is a cavity in the ground or rock where a plant or animal was buried.
Cast is an object created when sediment fills a mold and becomes rock.
FOSSILS TELL ABOUT THE PAST
-Changes in Environments: Iowa is said to have once been covered by a shallow sea.
- Changes in life: Superposition helps in this.
FOSSILS HELP THE DATING OF ROCKS
-Index fossils: fossils of organisms that lived during a relatively short, well-defined time span.
-Geologists can tell what part of the geologic column the fossil came from.

SECTION 5: TIME MARCHES ON (PG. 129)
- Grand Canyon shows lots of layers. Best place to look at Earth’s history.
- Geologic time scale: scale that divides Earth’s 4.9 billion year history into distinct intervals of time
Eons are the largest divisions of geologic time. They are broken down into eras.
Eras are the 2nd largest divisions and they are broken down into periods.
Periods are the 3rd largest divisions and they are broken down into epochs.
Epochs are the 4th largest divisions. The smallest.

PHANEROZOIC EON
Paleozoic Era: means “old life.” Lasted 540-248 million years ago. First era well represented by fossils. Beginning of this era there was no land organisms. The middle of this era plants developed. At the end of this era there were amphibians living on land and insects. This era ended with a mass extinction. 90% of the species perished.

Mesozoic Era: means “middle life.” This era lasted 248-65 million years ago. This era is known as the Age of Reptiles. Dinosaurs inhabited land and water. Later on birds and small mammals began to evolve. By the end 50% of species and dinosaurs became extinct.

Cenozoic Era: means “recent life.” This era began about 65 million years ago and continues to the present. We live in this era. This era is known as the Age of Mammals.

CHAPTER 2 NOTES: INTERACTIONS OF LIVING THINGS

SECTION 1: EVERYTHING IS CONNECTED
Ecology- the study of the interactions between organisms and their environment.

2 parts to an environment:
- biotic- all of the organisms that live together and interact with one another.
-abiotic- all of the physical factors of the environment. Like the water, soil, light, and temperature. These things affect organisms living in a particular area.

Organization of the Environment
- environments are arranged in different levels. (You illustrated each level in class)
Level 1: Individual organism (Example: you)
Level 2: similar organisms forming a population (Example: your family)
Level 3: different populations forming a community. (Example: all of the families that make up your neighborhood-they all come from different backgrounds)
Level 4: a community and its abiotic environment. This forms an ecosystem. (Example: all of the families and the plants, animals, lakes, ponds, air, dirt, etc.)
Level 5: All ecosystems forming the biosphere (Example: All parts of the world)

-populations are a group of individuals of the same species that live together in the same area at the same time.
-communities are all of the populations of different species that live and interact in an area.
- ecosystems are made up of a community of organisms and its abiotic environment.
-biospheres are the part of the Earth where life exists.

SECTION 2: LIVING THINGS NEED ENERGY
3 classification groups of how organisms obtain their energy
- Producers- use sunlight directly to make food. Most producers are plants.
- Consumers- organisms that eat producers or other organisms for energy.
4 types:
1. Herbivore- a consumer that eats plants. (Ex. grasshoppers, gophers)
2. Carnivore- a consumer that eats animals (Ex. coyotes, owls)
3. Omnivores- Eat both plants and animals. (Ex. Humans)
4. Scavengers- animals that feed on the bodies of dead animals. (Ex. crayfish, worms, crabs)

- Decomposers- organisms that get energy by breaking down the remains of dead organisms. Bacteria and fungi are examples. These are nature’s recyclers.

Food Chains/Food Webs
-food chains represent how the energy in food molecules flows from one organism to the next. Sometimes the energy source comes from many different organisms because rarely do animals eat one type of organism.

- food webs show the many different pathways possible for energy transfer among animals. Read on page 42 for an example and instructions on how to read a food web.

Energy Pyramids
-energy pyramids show the loss of energy at each level of a food chain. The base holds more energy because there are more plants available as an energy source. The next layer has less energy because the number of organisms decreases . The third level decreases in organisms and energy because of the type of organisms present. The top layer has the least number of organisms and the least amount of energy. See page 43 for a diagram.
Wolves and the Energy Pyramid
-Some consumers can control the populations of many other species.
- Wolves eat anything form lizards to elk. When the United States was being settled, gray wolves were almost wiped out. This in turn left no predators for the elk and the elk became overpopulated. This led to overgrazing and starvation to other animals because all of the producers were getting eaten by the elk since they eat producers. In order for everything to be balanced, the U.S. depends on the gray wolves for a consistent energy flow.

Habitat and Niche
- A habitat is an organisms environment in which it lives. An example would be that a wolf lives in forests, grasslands, deserts, and northern tundras. We live the same areas but in houses.
- A niche is an organism’s way of life within its ecosystem. This includes the organism’s habitat, its food, its predators, and the organisms with which it competes. An example would be the wolf’s habitat, grasslands, forest, deserts, etc. and the elk and lizards they eat, and its predators, other carnivores, and the competition of food with these other carnivores. A niche can also include how the organism affects and is affected by the abiotic factors in its environment. We effect our environment by polluting the air and in turn this pollution causes health problems. You can read about a wolves niche on pages 44 and 45 for a more detailed example.

SECTION 3: TYPES OF INTERACTIONS
Interactions with the Environment
- Most organisms produce more offspring than will survive. The biotic and abiotic factors in the environment control population size which causes the same population number to occur year after year. In “Finding Nemo,” Nemo’s siblings were eaten by a shark at the beginning. This is part of the interaction of organisms in its environment. If you noticed, Nemo’s parents produced a lot of eggs and only one of them, Nemo, survived.
- Limiting Factors: Limiting factors are when resources become scarce due to overpopulation of a species. Overpopulation can cause food, water, living space, and other needed resources to deplete or lessen which makes it a limiting factor.
- Carrying Capacity: Carrying capacity is the largest population that a given environment can support over a long period of time. When a population reaches its carrying capacity, limiting factors began to show themselves and the population gets smaller because the resources are not there.

4 Main ways Species/Individuals Affect Each Other:
1. Competition- when two or more individuals or populations try to use the same limited resource, food, water, shelter, space, or sunlight.
2. Predators and Prey- The organism that is eaten is the prey and the organism that eats the prey is the predator. Predators have to be able to catch their prey. Some of them use speed as their adaptation and others used a method of ambushing. Preys have ways of protecting themselves against predators with their own special adaptations. Some are poisonous to other predators or they have speed and run away, they can camouflage themselves, stay in groups, burrow, or hide within the environment.
3. Symbiosis- a close, long-term association between two or more species.
3 types of symbiosis:
- Mutualism: a symbiotic relationship in which both organisms benefit. An example would be a clown fish and a sea anenome. The clown fish benefits by having a shelter inside the sea anenome and the sea anenome benefits because the clown fish keeps it clean.
- Commensalism: A symbiotic relationship in which one organism benefits while the other organism is unaffected. An example would be you and the mites that live on your skin. The mites benefit because they feed off of your dead skin cells and in turn you are not harmed nor are you affected because you do not know they are there.
- Parasitism: A symbiotic relationship in which one organism benefits(parasite) while the other organism (host) is harmed. An example would be a cat and a tapeworm. The tapeworm lives inside of the cat’s stomach feeding off of the nutrients the cat gets from eating food. The cat eventually does not get the nutrients it needs and it will die. The tapeworm is the parasite in this example because it benefits and the cat is the host because it dies and is harmed.
4. Coevolution- a long-term change that takes place in two species because of their close interactions with one another. An example would be ants and a tropical tree. The ants protect the tree on which they live by attacking other herbivores that approach the tree. The tree has coevolved special structures on its stems that produce food for the ants and the ants also live inside other structures on the tree. The tree has coevolved because of this close long-term relationship between the ant and the tree.