Content Benchmark E.8.B.1 Students know the universe contains many billions of galaxies, and each galaxy contains many billions of stars. W/L Sample Test Questions Depth of Knowledge Level 1 1. What type of galaxy is the Milky Way? A. Elliptical B. Irregular C. Lenticular D. Spiral 2. How many galaxies are in our solar system? A. Zero B. Two C. Hundreds D. Millions 3. A galaxy consisting of large clouds of gas and dust with active star formation is most likely what type of galaxy? A. Elliptical B. Irregular C. Lenticular D. Spiral 4. A galaxy is composed of old stars and has no active star formation occurring. Which type of galaxy would this indicate? A. Elliptical B. Irregular C. Lenticular D. Spiral 5. How many stars are in our Solar System? A. One B. Two C. Hundreds D. Millions 6. The majority of stars in the Milky Way are A. blue stars. B. red giant stars. C. main-sequence stars. D. white dwarf stars. Depth of Knowledge Level 2 7. Use the diagrams below to answer the question. Diagram 1 Diagram 2 Diagram 3 Diagram 4 (from Holt, Rinehart, and Winston) Which illustration indicates a galaxy with mostly older stars that contains little gas or dust? A. Diagram 1 B. Diagram 2 C. Diagram 3 D. Diagram 4 8. Use the graph showing the Hubble law relating the distances of galaxies and speed moving away from the Milky Way to answer the question. Galaxy Speed vs. Distance 20000 Speed (km/s) 15000 10000 A 5000 0 0 30 60 Distance (mly [millions of light-years] ) What is the speed of the galaxy marked A in the graph? A. 5,000 km/s B. 10,000 km/s C. 15,000 km/s D. 20,000 km/s 90 120 9. Use the graph showing the Hubble law relating the distances of galaxies and speed moving away from the Milky Way to answer the question. Galaxy Speed vs. Distance 20000 Speed (km/s) 15000 10000 A 5000 0 0 30 60 90 120 Distance (mly [millions of light-years] ) What is the approximate distance in millions of light-years of galaxy A in the graph? A. 30 mly B. 60 mly C. 90 mly D. 120 mly 10. Use the graph showing the Hubble law relating the distances of galaxies and speed moving away from the Milky Way to answer the question. Galaxy Speed vs. Distance 20000 Speed (km/s) 15000 10000 5000 0 0 30 60 90 120 Distance (mly [millions of light-years] ) If a new galaxy with a speed of 15,000 km/s were discovered, it would be found at an approximate distance of A. 30 mly. B. 60 mly. C. 90 mly. D. 120 mly. Constructed Response Question Content Benchmark E.8.B.1 1. Use the following diagram and information to answer the questions below: Figure 1. Hubble Tuning Fork Diagram (From http://www.astro.virginia.edu/class/whittle/astr554/Topic2/t2_hubble_tfork.jpeg) A. Describe the three general types of galaxies originally identified by Edwin Hubble. B. Hubble used to believe this diagram was the evolutionary path of galaxies. Describe why he might have inferred this. C. What is the evidence that changed this idea? Content Benchmark E.8.B.1 Students know the universe contains many billions of galaxies, and each galaxy contains many billions of stars. W/L Answers to Sample Test Questions 1. D, DOK Level 1 2. A, DOK Level 1 3. D, DOK Level 1 4. A, DOK Level 1 5. A, DOK Level 1 6. C, DOK Level 1 7. B, DOK Level 2 8. A, DOK Level 2 9. A, DOK Level 2 10. C, DOK Level 2 Constructed Response E.8.B.1 Score Rubric: Response addresses all parts of the question clearly and correctly. 3 points A. Most galaxies are spiral galaxies, which have a nuclear bulge in the center and a few spiral arms. About one-third of all galaxies are elliptical galaxies. They have very bright centers and very little dust and gas. New stars do not form in elliptical galaxies. Irregular galaxies are those that don't fit into any other class. Their irregular shape may be the result of distortion caused by the gravitational attraction of spiral galaxies nearby. B. Hubble thought elliptical galaxies were “early galaxies” and spiral galaxies were “late galaxies”. He thought elliptical galaxies evolved into spiral galaxies. Scientists now know spiral galaxies rotate quickly, while elliptical galaxies do not. C. There is no way an elliptical galaxy could spontaneously begin rotating, as a result an elliptical galaxy could not turn into a spiral galaxy. 2 points Response addresses all parts of the question and includes only minor errors. 1 points Response does not address all parts of the question. 0 points The response is totally incorrect or no response provided.