Use these questions to test your understanding of the material for the final exam. If you get them wrong, you will be linked back to the relevant part of the notes.
Be sure you study them thoroughly (don't just get a quick fix for your mistake) so your overall understanding is improved.
Remember to go through the other three reviews for the final, since it covers the whole course.
1. An "open" universe is
a. one that will expand forever
b. one that galaxies can escape from, to enter other universes
d. one we can see out of to glimpse other worlds
2. The Universe is
c. at the critical density between open and closed
3. What came before the Big Bang is
a. described by subnuclear physics
b. a vexing philosophical question for science, as for religion and other disciplines of thought
d. revealed in our understanding of the Planck era
e. a sea of quarks that formed the raw material for the Universe
4. We will eventually be able to locate where the Big Bang occurred
a. by accurate measurements of galaxy velocities and distances
b. by measuring the redshifts of very distant quasars
d. by measuring anisotropies on the cosmic background radiation
5. How does the average density of the Universe affect its predicted fate?
b. if the Universe has a high density, its expansion is expected to reverse and it will collapse
c. if the Universe has a high density, it will eventually form many more galaxies than now
d. a high density Universe will have many more stellar collisions
e. if the density is too high, the Universe will form too many heavy elements
6. The cosmic background was discovered
a. as a faint noise component in the microwave spectral region
b. with the 100-inch telescope
d. as noise that interfered with TV broadcasts
e. in early efforts to detect other civilizations
7. One of the reasons the sky is dark at night is
a. we are in a dark part of the Milky Way
b. there is a lot of dark matter out there
c. the Universe is expanding
d. dust blocks our view in almost every direction
e. we look up, out of the Milky Way when the earth turns us away from the sun
8. If new measurements showed that the currently adopted value if Hubble's constant is two times too small, then we could conclude that the age of the Universe
a. was twice what we had believed before
b. was the same as we had believed before
c. was half what we had believed before
d. was four times what we had believed before
e. had changed but by an amount we could not estimate
9. The assumption that the Universe is homogeneous on very large scales is
d. the theory of equipartition
10. Hubble's Law implies that
d. the other galaxies were shot from the Milky Way
e. the Universe is not uniform
11. To a physicist studying the early Universe, unification is
a. a political movement to discredit unpopular theories
b. the concept that the fundamental forces of physics unified under extreme conditions
c. a theory combining aspects of biology and physics
e. a process for combining different theories in a computer code
12. The period of very rapid inflation in the early Universe solves the mystery of
a. why the Universe is so uniform
b. why the Universe is expanding
c. why balloons are sometimes used to illustrate the expansion
d. why there is so much empty space
e. how the ratio of hydrogen to helium is what it is
13. Understanding how subatomic particles like quarks behave is critical to understanding
a. why the cosmic background radiation is so uniform
b. the fate of Earth in the cosmos
c. conditions in the early Universe
d. why the cosmic background is in the microwave wave spectral region
e. the structure on the cosmic background
14. The "flatness problem" refers to
a. why space-time is not curved
b. how the Universe came out just at the density that balances its gravity
c. how spiral galaxies can maintain such flat disks
d. the extreme uniformity of the cosmic background radiation
e. why we do not see peaks in mass due to matter coming from other Universes
15. You are made of
16. We know that the Universe is only about 6% protons and neutrons - baryons - because
a. if there were more, the Universe would be closed
b. fusion reactions would have produced more lithium and maybe heavier elements if there had been more baryons
c. we don't really know this
d. because the things around us are made of 6% baryons
e. from measuring the properties of dark matter
17. The 3 degree cosmic background radiation originated when
a. the Universe got started in the Big Bang
b. the first stars began radiating
c. active galactic nuclei heated up interstellar dust
d. electrons were captured by protons to make the Universe transparent
18. The contrast in the structure on the 3K cosmic background tells us about
a. what kind of matter formed (fraction of baryonic or nonbaryonic)
b. where the first galaxies are
c. irregularities in the Big Bang
d. how the fundamental forces decoupled
e. where the cold spots are in the Universe
19. Dark matter
c. played a critical role in the merger of galaxies in the early Universe
d. no longer exists in significant quantities
e. glows faintly, allowing it to be observed with modern space telescopes
20. The early stages of development of the Universe a. are surprisingly well understood through a combination of physics and astronomy
b. are really hard to study because conditions were so extreme
d. may have been either steady state or big bang in nature
e. were a time when a totally different physics operated
21. The cosmic background radiation provides strong evidence that
a. the early Universe was very cold, only 3 degrees above absolute zero
b. stars formed almost immediately in the early Universe
c. the Universe has been expanding steadily forever
d. the Universe evolved from a hot, dense state
e. a lot of energy was produced through hydrogen fusion early in the life of the Universe
22. The cosmic background radiation is visible equally in every direction because
a. we are at the center of the Universe
b. we are not moving fast enough to Doppler shift the background by a large amount
c. we are looking back to when the Universe was young and opaque in every direction
d. the background has been scattered many times and now looks uniform
e. our telescopes are just not powerful enough to see far enough away to detect the nonuniformities
23. Astronomers cannot look back further than when the Universe was 300,000 to 500,000 years old because
a. before that, the Universe was too crowded with stars
b. photons were not produced until the Universe was 300,000 years old
c. dust in the early Universe absorbed the light
d. the Universe was made of dense, ionized gas that was opaque to light
e. our telescopes are not yet big enough to see that far
24. The "Big Bang" model of the Universe was confirmed when we
b. detected the 3K light left over and redshifted to its very low temperature
c. discovered the expansion of the Universe
d. saw a blinding light toward where the explosion occurred
e. detected X-rays from the hot gas in the explosion
25. Most of the helium was made
a. in the first generation of massive stars
b. in thermonuclear reactions in supernova explosions
c. in thermonuclear reactions in the first few minutes of the Universe
d. the helium was there from the beginning
e. we do not understand where all the helium came from
26. Grand unified theories suggest that, at extremely high temperature and pressure,
a. all the forces of physics can be explained in a single physical law
b. all the elements are unified into a single type of matter
c. fundamental particles like quarks unify into protons and neutrons
e. matter falls into a black hole
27. The concerns about global warming on the earth arise because
a. increases in the output of the sun as it evolves will make the earth warmer than it is now.
b. there is a natural fluctuation in the temperature of the earth, and we seem to be in an upswing.
c. changes in the orbit of the earth are bringing it closer to the sun.
e. there is just an irrational panic reaction among certain people.
28. Our understanding of the temperature on the earth a long time ago is based on
b. measuring the relative amounts of oxygen isotopes in ancient seashells
c. measuring tree ring widths in fossil, petrified trees
d. studying the types of plants that grew in different places
e. computer calculations that take the present temperature and weather patterns and work backwards
29. Over decade-to-century time spans,
a. independent measurements of the temperature on earth agree that it is going up
b. independent measurements of the temperature on earth disagree significantly
c. independent projections of the future temperatures are in close agreement
e. there is no clear conclusion that can be drawn about the temperature trend over the past century
30. What kind of experiment has proven most useful for finding planets around other stars?
a. using a very large telescope to take pictures sensitive enough to capture their light
b. listening for radio emissions from civilizations on them
d. measuring "eclipses" of the parent star by the exoplanet
e. using spectrographs to measure absorption features associated with planetary atmospheres
31. How many planets have we discovered outside the solar system?
32. Planetary debris disks are
a. dust and particles generated by collisions among small planetary bodies
b. material that falls off planets as they orbit
c. disks of material that remain after planets form
d. parts of the original circumstellar disk that formed planets
33. The number of planets we know are suitable for life are
34. The average temperature at the earth has been constant for the 4 billion years over which life has developed because
a. the output of the sun has been extremely constant over this period
b. the distance between earth and sun has changed in a way that canceled the changes in the sun
d. addition of oxygen to the atmosphere by plants has stabilized the temperature
35. The ice ages in the last few hundred thousand years seem to have been triggered by
a. changes in the output of the sun
b. the earth passed through a molecular cloud that absorbed sunlight that normally reaches earth
c. huge volcanic eruptions increased the amount of carbon dioxide in the atmosphere
d. small perturbations in the orbit and polar inclination caused changes in the climate
36. To determine when ice ages have occurred in the past, we
a. analyze the isotopes of oxygen in shellfish fossils
b. tunnel deep into the antarctic ice to see how thick it was in the past
c. study tree rings to see when growing conditions were unfavorable
d. study fossils to see when land animals had large amounts of insulating fat
37. Looking back over hundreds of millions of years, the earth
a. is warmer than average, due to human-induced global warming.
b. is at about an average temperature
d. is in a particularly unsteady state in terms of climate
e. has shown a steady warming trend as the output of the sun has increased
38. Planets in the "habitable zone" will
b. may form life if they are large enough to retain atmospheres
c. may form life if they retain atmospheres and have just the right amount of liquid water
39. Habitable zones are the regions
a. defined by the latitudes on a planet that stay warm during an ice age
b. around a star where water on the surface of a planet is likely to be liquid
c. where the stellar magnetic fields deflect comets and asteroids so they bombard the planets less
40. Life is unlikely to form on planets orbiting stars much more massive than the sun because
a. they burn their nuclear fuels and evolve off the main sequence too quickly
b. their strong gravity causes tidal locking of planets orbiting them
c. their high outputs make any planets around them too hot for life
d. cosmic rays and other radiation emitted by these stars are too intense for life
e. actually, we think life forms preferentially around such stars
41. Long periods when the climate was warmer than average were probably caused by
a. the mantle getting hotter and heating up the continents
b. the orbit of the earth getting smaller, so we were closer to the sun
c. the output of the sun going way up
d. the day being much longer because the earth was spinning more slowly on its axis
e. greenhouse warming due to carbon dioxide released by many volcanoes
42. The weather is difficult to predict because
a. we do not yet gather enough information for weather forecasters
c. weather systems are continually shifted by mountain ranges
43. Life could not form in the first few hundred million years of the formation of the earth
a. because the oceans were not yet salty enough.
b. because organic material had not yet arrived from outer space.
c. life probably formed but the traces have been obliterated by geological processes.
d. because the rapid bombardment of the earth by large bodies made it very hostile to life
e. because not enough carbon had been carried onto the earth by comets.
44. The most critical aspects of life are
a. sexual reproduction and being able to move
b. to harness energy and to reproduce
c. to grow cells and carry out photosynthesis
e. to breathe oxygen and exhale carbon dioxide
45. The very first forms of life we have found
a. have long since gone extinct
c. have survived apparently unchanged as the ultimate "living fossils"
d. are so primitive they do not have cells
e. are similar to life found on Mars
46. Stanley Miller's experiment is famous because
b. he was able to make RNA in the laboratory, showing how life reproduced
c. a huge portion of the carbon in his chemicals - 15% - appeared as life-like sludge in his beaker
e. he worked for a Nobel prize winning scientist.
47. Errors, or mutations, in the reproduction of early life
a. were virtually non-existent, because the life forms were so simple
b. were the underlying force for the development of improved life forms
c. were the big problem in getting life started at all
d. were a problem with RNA replication but did not occur any more when DNA developed
e. occurred at a very high rate because of the high rate of radioactivity of the sun.
48. DNA replication carries the information for new organisms because
b. DNA splits off a section of itself that grows into a copy like a lizard regenerating a lost tail
c. the phosphates and sugars of the DNA copy each other to carry the information
d. the DNA sends out RNA to the ribosomes with instructions on how to make new DNA
e. the helical structure of DNA allows it to move through the cell quickly, making copies.
49. Mars is a high priority target for space exploration because
a. we think there are intelligent Martians hiding from us there
b. we want to build space colonies on it.
d. the face on Mars suggests there is a dead civilization we might discover
e. its huge mountains and canyons would be highly scenic.
50. Mars is an attractive place to look for early life forms because
a. bacteria might have escaped from the early earth and colonized Mars
c. its red color might be from a primitive lichen
d. we can see its surface better than for any other planet
e. our spaceships have found materials under its surface the probably came from early life
51. Multiple forms of complex animal life first appeareda. after the K/T extinction. b. more than 3 billion years after the first life on Earth.
c. fairly quickly after the first life on Earth. d. as soon as nucleated cells developed.
e. once there was substantial oxygen in the atmosphere for them to breathe.
52. Sex was an important development toward advanced life because:
a. it makes the world go 'round.
b. it made animals want to reproduce more.
c. it greatly increased the genetic variety in living organisms
53. Nucleated, complex cells appear to have formed
a. by a mutation that created them directly from simple, un-nucleated cells
b. by cells developing ways to live together to their mutual advantage
d. within a few hundred million years of the end of the intense bombardment of the early earth.
e. once sex had been established.
54. Many Cambrian creatures are related to
a. arthropods, the group that includes spiders, insects, crabs, lobsters
b. vertebrates, the group that includes fish, amphibians
c. they had little relation to surviving life forms
55. The rapid development of a broad variety of animals in the Cambrian period occurred
a. because of the development of complex cells
b. the creatures are so unique, they must have come from another planet
c. for reasons we are not entirely sure of, although we have a number of ideas
56. A new development with the Cambrian creatures overall was
b. ability to operate on dry land
c. predators that fed on other animals
57. Judging by how long it took to happen, the most difficult step toward complex life was
a. development of bacteria that could reproduce and make food from water and carbon dioxide
b. development of nucleated cells
58. A disaster in which a large asteroid or comet strikes the earth is
b. unlikely because the moon can shield us from such events.
e. nothing to worry about because we can break it up with missiles and bombs
59. "Chaos" means ___________ to a scientist
a. the behavior of a system where very small changes can have very large consequences
b. the behavior of a NatSci102 class 30 seconds before the end of the lecture period
c. that he/she does not understand a system, but a more clever scientist might
d. the state of the dinosaur population right after the K/T impactor hit
e. the spray of fragments when an asteroid slams into a planet
60. The means by which the K/T impactor probably killed most of the dinosaurs is
a. fragments hit them on the head and fractured their skulls.
b. it disrupted the mantle of the earth and led to huge volcano eruptions.
c. they suffocated from noxious fumes emitted by the impactor.
d. carbon dioxide was released that caused a huge greenhouse effect.
61. After the K/T disaster,
a. the first mammals appeared.
b. small reptiles had survived, and they evolved into the first mammals.
c. primitive mammals like opossums became abundant relatively quickly.
62. Mass extinctions
a. appear to all arise from collisions of asteroids or comets with the earth.
b. occur roughly every hundred million years, probably from a variety of causes.
c. have only occurred once or twice in the history of the earth.
d. are responsible for the emergence of new species of animals every million years or so.
e. have been decreasing rapidly in frequency over the last billion years.
63. Evidence that an asteroid or comet killed the dinosaurs in the K/T extinction includes:
b. a thin layer of iridium-rich material in rock around the earth
d. the dinosaur death rate was highest on the Yucatan Peninsula
e. there is evidence of a huge blast wave from petrified trees that all fell in the same direction.
64. High iridium content indicates an object came from space because:
a. there is very little iridium in the earth
b. iridium is manufactured in the high pressure and temperature of a collision
c. iridium is made only in supernova explosions
d. iridium is a heavy material and therefore most of that in the earth has sunk to the center
e. the iridium on the surface of the earth is locked up in strong rocks.
65. Evidence that large asteroids hit the earth from time to time includes
b. evidence for huge tidal waves
c. the record of craters on other solar system bodies
d. petrified trees all aligned away from the impact sites
e. theoretical calculations of the frequency such impacts are expected
66. Convergent evolution means
a. All animals tend to evolve toward a single, highest form
b. Facing similar challenges, different types of animal tend to evolve toward similar solutions
c. Plants and animals are evolving toward a new type of organism
d. Conditions converged in the Cambrian era for development of a new variety of animals
e. Non-convergent forms of life are doomed to die out
67. Brain sizes
b. have tended to get smaller with time
c. have tended to get larger with time
d. have fluctuated a lot with time
e. take a big step toward smaller brains after a typical mass extinction
68. Sophisticated, thinking brains and complex nervous and sensory systems developed
a. to allow location of easily-digested foods
c. in the era of dinosaurs for the first time
d. a number of times, but earlier instances were eliminated in mass extinctions
69. Development of civilization on Earth has waited until sophisticated, thinking brains evolved and
a. visitors from outer space passed on the basic secrets of civilized life
c. major predators such as saber-toothed tigers became extinct
e. the climate entered a mild period that made it easier to grow food
70. The number of civilizations we might be able to receive radio signals from
a. is very hard to estimate - we can only try and see what happens
b. is very large, and we should do so very soon
c. is obviously so small that we should give up trying
d. depends critically on our determining the number of stars in our galaxy
71. The probability of a "fair" coin coming up heads is 1/2. What is the probability of it coming up heads three times in a row?
72. Animals with relatively large brains
a. are always capable of sophisticated thinking
b. might just be extra-good at sensing and hunting their prey
c. are at a disadvantage because of the demands the brain puts on their systems
d. generally are sea animals because of the difficulty of bearing the weight of the brain on land
73. Infant humans
a. use most of their body energy to support large and growing brains
b. are so uncoordinated because their brains are still tiny
c. have brain sizes typical of those of other mammals of similar size
d. cannot walk because their brains are too heavy
e. have brains of the primitive snatch and eat kind, like alligators
74. The biggest uncertainty in how many civilizations there are right now in other planetary systems around us is probably
a. the likelihood that even primitive life could get started on a habitable planet
b. the number of planetary systems around other stars
c. how long a civilization lasts before it dies out or destroys itself
d. whether large brains would develop once another planet had complex animals on it
e. how many stars there are that are suitable for planet systems with life
75. The further something is away from us, the ______ it appears.
76. To search for extremely distant objects like the first galaxies to form, you need
77. In addition to looking for the first galaxies to form after the Big Bang, JWST will also be useful
a. for studying lifeforms on Mars
b. for searching for old stars
c. for searching for gamma-ray bursts
78. The first planet detected outside of the Solar System
a. is just like ones in the Solar System
b. is much closer to its parent star than any in the Solar System
c. was found by taking a photo of it
d. is unique in the entire universe
e. has not had any of its properties measured
79. The Kepler mission has found planets that
b. are on average must smaller than the Earth
c. are on average the same size as Mars
d. are on average larger than Jupiter
e. are almost as big as small stars
80. The Kepler mssion has found ________ planets in habitable zones.
e. that we cannot determine the number of
81. When estimating the total number of planets in the Milky Way
a. it is important to realize that planet formation is difficult
b. it is important to consider the types of stars in the Milky Way
c. it is important to consider how rapidly stars rotate
d. it is important to consider how planet detection techniques can bias results
e. it is important to consider how reflective planets are
82. We have discovered few planets as distant from the parent star as Jupiter is from the Sun
a. because such planets don't exist
b. because it takes several decades of observing to be sure that such a planet is real
c. because most planets are very close to their parent stars
d. because Jupiter-like planets produce smaller observable effects
e. because planets far from their parent stars are too hot
83. The difference between reionization and recombination is
a. reionization refers to helium while recombination refers to hydrogen
b. reionization is caused by starlight
c. recombinaton is caused by heating
d. recombination occurs later than reionization
e. neglible as they refer to the same event in the history of the universe