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60 Cards in this Set
- Front
- Back
we have learned about the late heavy bombardment by studying.. |
craters on the moon and rocks returned by the Apollo astronauts |
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the argon that exists in the earth's atmosphere today |
accumulated over time from the decay of potassium |
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the productions of our protective ozone later was enabled by |
the dissipation of hydrogen form the earth's atmosphere` |
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to learn a rock's age, we must |
measure the ratio of different isotopes within it |
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suppose that jupiter didn't exist and there was no planet in the solar system between mars and saturn. how might this have affected the earth? |
earth would most likely have been hit by more comets |
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which of the following ideas gives us the most confidence that there could be life on planets around other stars |
the laws of physics and chemistry seem to apply everywhere |
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which of the following is not a greenhouse |
nitrogen |
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a rock's type (igneous, metamorphic, sedimentary) tells us |
how it's made |
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the greenhouse effect refers to molecules in the atmosphere that absorb |
infrared radiation |
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which of the following was a major component in the atmosphere of early earth? |
carbon dioxide |
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radiometric dating now allows us to determine earth's age to the accuracy of about |
40 million years |
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the timing of the last sterilizing impact is important because it probably tells us |
when life could have take long-term hold on the earth |
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how did oxygen become so abundant in the earth's atmosphere |
it was released by life through the process of photosynthesis |
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were it not for the greenhouse effect, the earth's average temperature would be |
somewhat lower (10s of degrees) |
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the primary reason that earth has retained a lot of internal heat is because of its |
relatively large size |
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the earth has far less carbon dioxide in its atmosphere than does venus because |
earth's carbon dioxide is locked up in carbonate rocks |
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the term "snowball earth" refers to |
one in a series of very deep ice ages that occurred more than 500 million years ago |
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earthquakes are important tools for geologists because the resulting vibrations |
allow the study of the earth's internal structure |
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if earth had more greenhouse gases in its atmosphere, it would |
heat up |
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which of the following serves as evidence that the earth's interior is not solid |
plate tectonics and the magnetic field |
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which of the following applies to dna |
it stands for deoxyribonucleic acid it is the basis for heredity it transfers information from one generation to the next |
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a covalent bond is |
when a pair of electrons is being shared between two atoms |
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life on earth uses how many different amino acids |
20 |
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which is not a key property to life |
the ability to violate the second law of thermodynamics |
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natural selection is the name given to |
the mechanism by which advantageous traits are preferentially passed on from parents to offspring |
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the RNA molecule uses ___ while the DNA molecules uses ___ |
uracil, thymine |
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in a DNA molecule, the base cytosine connects to |
guanine |
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people belong to which kingdom |
eukarya |
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in a methane molecule, how many pairs of electrons is the carbon atom sharing with other atoms? |
4 |
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the earth's atmosphere began to accumulate oxygen about 2.5 Gyr ago. the principle agent responsible for the oxygen was |
cyanobacteria (blue-green algae) |
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there are approximately how many base pairs in human DNA |
10^9 |
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based on DNA studies, it seems that all life on earth |
shares a common ancestor |
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how did oxygen get into the earth's atmosphere |
it was released by life through the process of photosynthesis |
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which of the following is not a source of energy for at least some forms of life on earth |
energy release from plutonium |
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which of the following plays little role in allowing for life to flourish on the earth |
the moon protects life from most cosmic rays |
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an organisms heredity is encoded in |
DNA |
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silicon has been suggested as a basis for life because |
a silicon atom makes four molecular bonds as does a carbon atom |
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which of the following is not true about prokaryotes |
all forms require oxygen |
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what is the key observational evidence that supports the idea that life on earth has evolved through time |
the fossil record, revealed in geological layers of different ages, shows that life on earth has become more complex over time |
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which of the following is not an argument for the superiority of water over ammonia or alcohol for supporting life |
water is found in the interstellar medium but alcohol and ammonia are not |
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what molecules were created in the miller-urey experiment |
amino acids |
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in the miller-urey experiment, the initial compositition of the gases was |
ammonia, methane, and water |
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currently, we think the miller-urey experiment might not replicate the early earth accurately because |
our understanding of the early earth's atmosphere has changed |
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the earth's atmosphere began to accumulate oxygen about 2.5 Gyr ago. the principle agent responsible for the oxygen was |
cyanobacteria (blue-green algae) |
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we think the organics found in the tagish lake meteorite were formed |
in a cold dark molecular cloud |
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in the tagish lake meteorite, the fact that the organix molecules were formed before the solar system was established by |
examining the isotopic ratios of certain elements |
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how did oxygen get into the earth's atmosphere |
it was released by life through the process of photosynthesis |
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we're not yet capable of detecting life on planets around other stars. however, as our technology develops, our first real chance of detecting life will probably come from |
examining spectral lines in the atmosphere of distant planets |
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the origin of life on earth most likely occurred |
between 4.5 and 3.5 billion years ago |
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the first living organisms were probably |
cells without nuclei that used RNA as their genetic material |
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the importance of the miller-urey experiment is that |
it showed that natural chemical reactions can produce the building blocks of life |
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early life arose in an oxygen-free environment, but if any of these microbes had come in contact with oxygen, the most likely effect would have been |
they would have been killed |
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what is the evidence that all living organisms have evolved from a common ancestor |
essentially all life uses the same genetic code DNA shows remarkable similarities among all life forms not only useful but also "junk" DNA is found to be similar among different organisms |
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the cambrian explosion refers to |
a dramatic increase in animal diversity beginning about 545 million years ago |
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how did life arise |
DNA studies suggest that the first life may have lived in hot water near volcanic vents & this is a subject of scientific study |
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"RNA world" refers to |
the idea that RNA was life's genetic material before DNA |
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which of the following could be the most likely benefit from creating artificial life |
we'll gain insight into the origin of life on earth |
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the hypothesis that an asteroid impact killed the dinosaurs seems to be |
well-supported by the geological evidence |
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lets say you invent a laser system that can protect the earth from tunguska-sized impacts. about how often would you have to use it |
ever few hundred years |
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based on DNA studies, it seems that all life on earth |
shares a common ancestor |