Second Semester 8th Grade Science Review (2008/2009)

Astronomy (Chapters 22/23)

  1. Describe the contributions of the 7 astronomers described in Chapter 22 Section 1.

Ptolemy, Copernicus, Tyco Brache, Kepler, Galileo, Newton

  1. According to the big bang theory, the age of the universe is about:

Age is 4.6 – 4.7 Billion Years ago

  1. Astronomers often place telescopes on mountaintops because:

Less atmosphere, thinner air, less moisture and light pollution.

  1. Describe the two types of telescopes. Include a description of the advantages and disadvantages of each

Reflecting and Refracting. (See notes and book for description and advantages and disadvantages.)

  1. If you see a quasar that is 6 billion light-years away, how old is the light you are seeing?

6 billion years ago.

  1. What is the Big Bang Theory? What evidence is used to support it?

A large explosion started the universe, galaxies moving away, and background radiation supports the theory.

  1. What type of galaxy is our Milky Way galaxy?

Spiral

  1. What type of stars are the majority of stars in our galaxy?

Main Sequence

  1. How do we measure the distance between objects in space?Light Years
  2. How would you describe the hottest stars in the sky? Blue
  3. If two stars are different colors, we can infer that they have different:Composition and Temperature
  4. When you look at white light through a glass prism, you see a rainbow of colors called: Spectrum
  5. The actual brightness of a star is called its:Absolute Magnitude
  6. The apparent change in location of an object is called:Parallax
  7. When the core of our sun runs out of hydrogen, and falls off of the main sequence, it will first become a Red Giant___ start before it eventually becomes a white dwarf.
  8. A Black Hole forms when the leftovers of a supernova are so massive that they collapse to form a dense object whose gravity is so strong that light cannot escape it.

Plate Tectonic

  1. Why is the Plate Tectonic Theory a better theory than the Continental drift Theory? Explains in more detail the movement of the plates and why we have seismic activity.
  2. If new crust is being created at the mid-ocean ridges, then why is the earth not getting larger?Subduction and Convergent Boundaries
  3. The Continental Drift Theory was not accepted when proposed because:Couldn’t explain how plates moved apart.
  4. Alfred Wegener thought that all of today's continents were once joined in a huge continent that he called:Pangea
  5. Describe the three main types of plate boundaries. How do the plates move, what land features are formed, examples, and if they include a Subduction zone.

Convergent Boundary – Move together Compression Stress, Divergent Boundary Move apart Tension Stress, and Transform Boundary Horizontal movement. Subduction zoneis one plate dives under the other and is melted into magma.

  1. Sea-floor spreading occurs at a Divergent boundary.
  2. What evidence was used to support the theory of continental drift?Pangaea

Rock and Rock Cycle Chapter 15

  1. Be able to interpret The Rock Cycle from a diagram. Know Louie the Longhorn
  2. What is the process where sediments are hardened into rock by compaction and cementation?Lithification
  3. What type of sedimentary rock that forms when oceans and rivers evaporate? Chemical
  4. Fossils are found mostly in _Sedimentary_ rock.
  5. Molten rock below the earth’s surface is called: Magma
  6. Igneous rocks that cool slowly have this type of texture: Coarse grain
  7. Layers in sedimentary rock are called: Strata
  8. Process where sediment is squeezed or pressed together:Compaction
  9. Igneous rocks that are denser, darker in color, and are composed of mostly of Fe and Mg: Mafic
  10. Rocks formed from magma or lava are called: Igneous
  11. What is weathering and what are its agents? The breaking down of rock. Abrasion, Ice Wedging, Wind, Water, etc.
  12. What is erosion and what are its agents?Transportation of sediment from one place to another.
  13. A type of igneous rock that forms when magma cools deep in the earth:Intrusive
  14. What is the process that involves heat, pressure, melting, cooling, and sedimentation which changes

rocksfrom one type to another.Rock Cycle

  1. What is the type of metamorphic rock that has parallel bands?Foliated

Genetics and the Environment - Chapter 10

  1. Describe the three types of symbiotic relationships. Give an example of each.

Mutualism, Commensalisms, and Parasitism

  1. Describe the predator-prey relationship and give an example.See notes
  2. When a population grows larger than its carrying capacity, limiting factors in the environment cause the population to: Population will decrease
  3. Define incomplete dominance. Each allele has its own degree of influence.
  4. If you cross a plant that has yellow seeds (with the genotype Yy) with a plant that has green seeds (with the genotype yy), the possible genotypes and phenotypes in the offspring are:

Yy

y

y

Genotypes: Yy, yyPhenotypes Yellow/GreenRatio Genotype 0:2:2 (YY,Yy,yy) 0%, 50%, 50%

Phenotype 2:2 (50%50%)

  1. A trait that helps an organism survive in its environment is called a(n)

Adaptation

  1. The key to natural selection is:

Successful reproduction

  1. Describe and give an example of the four steps in Darwin's theory of natural selection.
  2. What is a learned behavior?Behavior gained by watching other people.
  3. The organism’s appearance is known as its:Phenotype
  4. A tick sucks blood from a dog. In this relationship, the tick is the _Parasite___ and the dog is the _Host___.
  5. What conditions would make resources such as water, food, or sunlight are more likely to be limiting factors? When population approaches carrying capacity

Structure of the Earth

  1. Tectonic plates are large pieces which earth layer? Lithosphere
  2. Tectonic plates move on top of which earth layer? Asthenosphere
  3. Earth's oceanic crust is ____ ( thinner, thicker) and (less dense, denser)than the continental crust.
  4. Which layer is the densest?Inner Core
  5. _plasticity______is the ability of a solid to flow like a liquid when put under pressure.
  6. Folded mountains are caused by _compression______.
  7. The _crust______is the only layer of the Earth that we have actually seen.
  8. _pressure______keeps the inner core from becoming liquid.
  9. In which layer of the Earth are convection currents believed to occur? asthenosphere

Topographic Maps

Use the topographic map below to answer the following questions.

  1. What could be represented at point B?Plateau
  2. What is the elevation at point A?54 m
  3. What is the contour interval for this map?10 m
  4. Where would you find the steepest slope on this map?east side
  5. If you travel from point B to point C, you would be traveling?uphill

Geologic Time/Relative Dating/Absolute Dating

  1. The shortest era is called the _Cenozoic______Era.
  2. Scientist believe that the age of the earth is4.6 billion years old
  3. The smallest division of geologic time listed is a (n)Epoch
  4. The largest period of geologic time listed is a (n)eon / era
  5. The oldest fossils, which are blue-green algae, are called stomatolites
  6. The possible cause of the extinction of the dinosaurs at the end of the Mesozoic Era wasasteroid
  7. The era we now live in is the _Cenozoic______Era.
  8. At the end of the Paleozoic Era, extinction of many organisms occurred. What caused this to happen?Pangaea formed, climate changed
  9. Scientist divide geologic time into eras based onmajor changes
  10. During which era did the greatest extinction occur?Mesozoic
  11. Fossils areremains of once living organisms
  12. Why do so few fossils remain today?Soft bodies, weathering and erosion.

Structure of the Earth/Faulting/Folding

  1. The type of stress that involves rocks being squeezed together is called _Metamorphic______.
  2. The stretching or pulling apart of rocks is called:tension
  3. Folded mountains are caused by _compression______.

Be able to correctly label a normal, reverse, and strike-slip fault

Be able to identify the hanging wall and foot wall of a fault

Be able to correctly label each type of fold.

Waves (Chapter 7 )

Label diagram below.

1. Crest 2. Wavelength 3. trough 4. wave height

  1. Label diagram below
  1. What is a medium? Substance a wave can travel through
  2. What type of wave interaction explains why sound waves can be heard around corners? diffraction
  3. Waves transfer :energy
  1. Refraction occurs when a wave enters a new medium at an angle becauseit changes speed
  1. Which waves do NOT require a medium to travel?electromagnetic
  1. Light waves travel fastest throughempty space
  2. Sound waves cannot travel throughempty space
  3. Interference__ is the result of two or more waves overlapping.
  1. As the frequency of a wave increases, the energy_ increases.
  1. The number of waves produced in a given amount of time is called the _Speed___ of a wave.

Below are illustrations of waves. Study the illustrations, and answer questions.

  1. Which wave has the largest amplitude?B
  1. Which wave has the LEAST energy?C
  1. Which wave has the longest wavelength?all the same
  2. Electromagnetic waves are made ofvibrations of electric and magnetic waves
  3. The electromagnetic spectrum is arranged according toWavlength
  4. A(n) _EM___ can travel through space or matter.

Force and Motion

  1. Friction is a force that opposes motion
  1. A forceexpressed in Newton and causes changes motion and is a push or pull
  1. If passengers on an airplane watch another plane passing by them, their reference point is theThey are, the plane watching is RP
  2. The distance traveled divided by the time it took to travel that distance is equal to an object'sSpeed
  1. You are in Chicago, Illinois. You decide to head south to Austin, Texas. In 1 hour, you travel 80km.

Your velocity is80 km/hr south

  1. If a bus traveling 15 m/s south increases its speed to 20 m/s, it has changed itsvelocity, speed and acceleration
  1. A car traveling 20 m/s south enters a new highway going east at 20 m/s. The car has accelerated
  1. Decreasing velocity could be referred to as deceleration
  1. The moving blades of a windmill are an example ofcentripetal acceleration
  2. Which of the following situations involves a force being exerted?
  3. Balanced forces applied to an objectproduces no movement net force of zero
  1. A force that opposes motion between two surfaces that are touching isfriction
  1. A good rule to observe when you are around a swimming pool is "no running." The wet deck around the

Pool is very slippery because offluid friction

  1. Your class and another class have a tug-of-war contest. In order to win, your class mustcreate a greater force in the opposite direction
  1. One Saturday you go on a picnic. Although there is a slight breeze, the napkins stay on the tablecloth

Because ofstatic friction

  1. Because the moon's gravitational force is one-sixth that of Earth's, an astronaut's weight on the moon is1/6 that of earths weight.
  1. A golf ball and a bowling ball are moving at the same velocity. Which has more momentum?the bowling ball
  1. According to Newton's first law of motion, a moving object that is not acted on by an unbalanced force

Will remain in motion

  1. Newton's third law of motion states that if a force is exerted on an object, another force occurs thatequal and opposite

You have four vehicles, all driving at the same velocity side-by-side on a four-lane highway. They are a fully-loaded truck, an empty truck, a midsize van, and a small car.

  1. Which one has the MOST momentum?the loaded truck
  1. If all the vehicles brake at the same time because there is a collision ahead, which one will come to a

Complete stop FIRST?Small car

  1. Inertia is used when explaining Newton'sfirst law
  1. If a car driver suddenly makes a sharp turn, the passenger slides to the side of the car because ofinertia