1 A) barred spiral, irregular, and Seyfert B) Seyfert, radio, and quasar C) spiral, elliptical, and irregular D) old, young, and intermediate 2 A) They contain mostly old (Pop II) stars. B) They have little dust or cold gas. C) They have prominent spiral arms. D) Stars are distributed smoothly throughout their volume. 3 A) About 30% of them collide and become black holes. B) About 50% of them become binary stars. C) The evolution of all the stars in the larger galaxy is accelerated. D) Nothing happens to them, except that their orbits may change. 4 A) Collisions and mergers play an important role in shaping galaxies. B) Collisions have a strong effect on the evolution of stars. C) Collisions are extremely rare. D) Both b and c. 5 A) 10 megaparsecs. B) 25 megaparsecs. C) 60 megaparsecs. D) 130 megaparsecs. 6 A) they can detect it with radio telescopes. B) the galaxies in clusters move faster than expected on the basis of the material visible in them. C) it is the only way to explain the black holes in active galaxies. D) they have detected neutrinos from unseen sources. 7 A) barred spiral, irregular, and Seyfert B) Seyfert, radio, and quasar C) spiral, elliptical, and irregular D) old, young, and intermediate 8 A) The center B) The spiral arms. C) Outside the galaxy in radio lobes. D) A thin shell surrounding the galaxy. 9 A) Their nuclei have abnormally low luminosities. B) They contain no gas clouds. C) The radiation from their cores fluctuates rapidly. D) Most are elliptical galaxies. 10 A) Their light varies rapidly. B) Their spectra show immense redshifts. C) They are very bright. D) They are very faint. 11 A) We can measure their size on the sky, which means they are small and near. B) They emit radio waves that larger objects cannot do. C) Their light varies rapidly, implying small radius. D) They are very far away, and thus are younger and less expanded. 12 A) An immense black hole. B) Intense magnetic fields C) A supernova explosion. D) None of the above. 13 A) A heavy contact lens. B) A massive object that bends the space around it, causing light passing it to bend. C) An extremely massive refractor telescope. D) A lens that is affected by gravity. 14 A) The Coma cluster / 500. B) The Pleiades / 3 other. C) The Local Group / 30. D) The Beehive Association / 100. 15 A) A region in the Universe where there are almost no galaxies. B) A part of the sky where no galaxies are visible to us because of obscuring dust in the Milky Way. C) A part of the sky that astronomers cannot observe due to bright emission from interstellar dust. D) The region of the Solar System where it is too dangerous to send spacecraft.
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