Universe Final Exam
Which part of the Earth system includes all minerals, rocks, sediments, soils, etc:
geosphere
what process drives the metabolism for all living cells? That is, what chemical process is behind the storage and release of energy within the cell to make most all chemical structures:
the ATP cycle
What is the relationship between Newton's three laws of motion and the universal law of gravity and Kepler's three planetary motion laws:
Kepler's laws can be derived from Newton's laws, explaining "why" the planets move as they do
Models of the solar system typically used the AU for distance scale. The unit is defined to be equal to the:
average distance between the Earth and the Sun
Why is it that the majority of extrasolar planets discovered to date resemble "hot" Jupiter type worlds:
because the Doppler shift and transit detection techniques will most easily find massive planets with orbits close to their parent star
Why are the claims for the discovery of the most ancient microfossils still subjective and controversial:
because too few examples exist and it is not clear whether they are of biological or non-biological origin
If life exists on Mars today, it will most likely be found:
beneath the surface, perhaps in caves
A fossil is found in a layer of strata above another layer dated at 10 million years and below another layer dated at 5 million years. From this we can deduce the age of the fossil to be:
between 5 and 10 million years old
Extrasolar planets:
can be found by observing their gravitational effect on their star
What is one of the major reasons why early life would need to form cells:
cells help to protect fragile biochemical molecules from the outside environment
Scientists who are involved in a field of astrobiology research will:
come from many branches of science as the research is very much interdisciplinary
Although still a characteristic that is difficult to define, it is though that the ratio of an organism's brain weight to its body weight would be roughly proportional to its:
intelligence
Our bodies consist mostly of only 4 common elements which dominate the molecules found in life. Which of the following is not one of those four elements:
iron
The knowledge we have gained through astronomy has shown us that the Earth:
is just one planet orbiting an ordinary star in a vast universe
Saturn's icy moon Enceladus is a strong candidate for life possibilities because:
it has a geyser of water vapor spraying out from its surface showing liquid water clearly exists just beneath the surface with an internal heat source
Even though titan has an atmosphere, possible liquid methane on its surface, some internal heat, and plenty of carbon-containing compounds, it is not an ideally suitable place for life mainly because:
it is far too cold for active chemistry, and methane is not a very good biological solvent
Why is the chemical evolution model, describing life as originating over a very long time through increasingly complex chemical reactions and structures, preferred by scientists over other theories for the origin of life on Earth:
it is the theory that best fits the available data at the current time
Which of the MOST important property of the element carbon that makes it ideal as a fundamental building block of biological molecules:
it readily forms multiple chemical bonds with itself and other elements, allowing a wide variety of complex molecules to form
What is the most important role that the carbon cycle plays in the regulation of the Earth's climate:
it regulates the surface temperature by varying the amount of carbon dioxide in the atmosphere
If life beneath the surface of Europa exists, it would most likely exist because:
it utilizes the energy from tidal stresses which heat the moon's interior, possibly creating volcanic like vents on the bottom of the subsurface ocean
Discoveries of the wide range of extrasolar planets have shown us that in regard to the formation of solar systems:
the general features of the nebular theory are correct but some modifications are needed
The ancient water erosion features on the surface of Mars suggest that the planet must have had a much:
warmer, thicker atmosphere in the past
Analysis results from the studies of rocks and soils by the Mars exploration rovers Curiosity and Perserverance give convincing evidence that liquid water:
was once plentiful, long ago, on the surface of Mars
For a planet to be considered habitable, what is the most critical requirement:
water in liquid form must potentially exist on or under the planetary surface
The electromagnetic spectrum of a star refers to:
the set of frequencies of radiation that the star can emit
Even with all the uncertainties in the Drake equation, we exist on the Earth, thus the minimum value of N in the equation must at least be equal to what value:
1
In the lab on "habitability" in the planetarium, you saw how the energy received from a star by a planet decreases according to the "inverse square law". In words this law states that the energy received is inversely proportional to the square of the orbit radius (E=1/r^2) Thus, for a planet like Jupiter whose orbit is 5 times the radius of Earth's orbit, it receives:
1/25 the energy that the Earth receives
We are focusing on searching for life around stars like our sun partly because such stars live for a very long time. About how long does a star like our sun live with a fairly constant energy output on the main sequence:
10 billion years
Although the universe is though to have existed for 14 billion years, the geologic age estimate for the earth and thus our solar system in general is only around:
4 to 5 billion years
As part of the SETI program, we sent a strong radio signal in the direction of the globular star cluster M13 (which is 25,000 light-years away) in 1974. assuming a technological civilization received and would respond to that signal, approximately how soon might we expect the response:
50,000 years
The most recent global mass extinction event is referred to as the K-T extinction which eliminated the last dinosaurs on Earth. This event occurred approximately how long ago?
65 million years ago
What is the latest status on the search for a "goldilocks" planet, i.e., another Earth from our observation missions:
A few dozen somewhat earth like planets have been detected that lie in the habitable zone of other stars
The importance of the oceans and water vapor in the Earth's atmosphere was stressed because of the way both can add to or remove energy from the atmosphere. this is because:
A large amount of energy is involved in the processes of evaporation and condensation of water
Which of the following is not true about the scientific theory:
A scientific theory is essentially an educated guess
Since chemically based life requires biological molecules to come into contact with each other, this will require a planet with
A thin liquid medium on or below the surface
Which three fields of science are the most relevant in the study of life in the universe:
Astronomy, geology, and biology
I lectured on the possible human exploration of Venus and presented a video describing missions to Venus that could be easier, cheaper, and safer than going to Mars. What particular characteristic of Venus would make human missions to it better in this way:
Because there is a region in the upper atmosphere of Venus that is the most Earth-like location in the solar system. That region has a pressure and temperature comparable to the Earth so humans could survive in an airship needing only oxygen and minimal protection from the somewhat hotter temperatures and a weakly acidic environment
What is considered the basic unit of life on Earth:
Cells
What is a major difference between prokaryotes and eukaryotes:
Eukaryotes have nuclei in their cells; prokaryotes do not.
The matter that makes up life (atom and molecules), in facts, the actual basic molecules that serve as the building blocks of life have been found to exist:
Everywhere we have the ability to detect them, the Earth, other planets and moons, meteorites, even in interstellar dust and gas clouds
Of the six basic properties we defined for life, which one do biologists consider the most fundamental to insure that life remains successful and that allows it to establish itself on a planet's surface, for example:
Evolutionary adaptation
Which component of Earth's geology has helped to shield the Earth's atmosphere from energetic charged particles of the solar wind emitted by the Sun. These particles would have gradually stripped away the atmosphere into space and would increase the harmful radiation on the surface of the Earth:
Global magnetic field
The Greenhouse Effect is the result of:
Infrared radiation from the surface of the Earth being trapped by the Earth's lower atmosphere
Because of its dynamic volcanic activity, large sulfur concentration, and closeness to Jupiter's radiation environment, which of the four Galilean moons is least likely to harbor life:
Io
Even though Jupiter's moon Io is similar in size to our geologically dead moon, it is more geologically active than the earth, even possessing active volcanoes on its surface. How can this be:
Io experiences tidal gravitational forces due to its close elliptical orbit to Jupiter and orbital resonances with other Galilean moons; this causes large flexing and distortion of its interior generating heat
In Copernicus's theory, retrograde planetary motion is explained simply as:
It is the result of Earth's motion: as Earth passes another planet, that planet appears to move backward as seen against the background stars
Life on earth can use a variety of different carbon and energy sources for its metabolism. However, the one thing that all living organisms on earth require in order to survive is:
Liquid water
Living organisms need food: your car needs gasoline. What kind of energy do we consider food and gasoline to possess?
Potential
The most significant difference between the astronomical theories of Ptolemy and Copernicus is:
Ptolemy's theory is Earth-centered, whereas Copernicus's is sun-centered
Which of the following places the structures in our own part of the universe in order of increasing (smallest to largest) size:
Solar system, Milky Way, Local Galaxy Group, Galaxy Supercluster
The astronomical object in our sky which plays the most fundamental role in our lives is the:
Sun
In a few billion years when the sun runs out of nuclear fuel and expands to become a red giant, it's habitable zone will move outward, beyond the orbit of the earth. Earth will then be in an orbit more like the environment of Venus today, receiving much more energy from the Sun. What is predicted to happen to the Earth as the Sun changes this way?
The earth will experience a runaway greenhouse effect with its oceans evaporating followed by a gradual loss of the atmosphere
While force dominates in keeping negative electrons orbiting the positive nucleus of atoms:
The electromagnetic force
The theory for the formation of the solar system leads to a natural state of having terrestrial planets in the inner solar system and gas giants in the outer solar system with the orbits of the planets being nearly circular and in the same direction around the sun:
The nebular theory
What observation can be made in the sky by anyone on the Earth that strongly suggests the Earth has a spherical shape? The Greeks certainly used this observation to infer the Earth was a sphere:
The shadow of the Earth is curved during a lunar eclipse
Kepler's second law established that the farther a planet is from the sun:
The slower the planet moves
What prominent uplifting geologic phenomenon is typically found along the boundaries of tectonic plates and is associated with atmospheric effects as well as geologic ones:
Volcanoes
Based on the way scientists view the study of astrobiology, failure to find life on any other world would mean:
We have learned important lessons about the conditions that made life on earth possible
What is the typical view of the martian surface from a spacecraft lander sight:
a cold, dry, sandy, and boulder-strewn desert
We discussed a need to give a definition for life which may not be easy. For example, a virus is best described as:
a complex biochemical mechanism
Which of the following extrasolar planets would be the easiest to detect using the Doppler Shift method:
a massive planet close to its parent star
The drake equation calculates a value for the number N. What does N represent:
a number of technological civilizations with the ability to communicate in our galaxy
What is the "water hole" in reference to the SETI programs:
a quiet part of the radio spectrum where searched for extraterrestrial signals are made
The concern for global warming for the earth is that carbon dioxide increase and its associated temperature increase in the atmosphere could lead to:
a significant climate change with an increased greenhouse effect as on Venus
The lack of large impact craters on the surface of Europa is consistent with:
a subsurface ocean of water because large impacts will break the thin crust causing water and slushy ice below to flood out and over time resurface the crust
What feature is common to several of the large icy moons of Jupiter (and some of Saturn's as well) that makes them good candidates in the search for life in the solar system:
a subsurface ocean or sizable water mantle region exists beneath an icy shell
What did astronomers Lowell and Schiaparelli (among others) claim to see on the surface of Mars over 100 years ago that led to such great speculation about intelligent life (even a vast ancient civilization) on Mars:
a system of intricate canals to transport water from the poles to the equatorial regions
Among the possible sources of different life-originating organic molecules believed to be present on the surface or in the oceans of the early Earth, scientists include:
all of the above
which of the following is not a difficulty associated with interstellar travel:
all of the above are difficulties
which of the following factors influence the surface habitability of a planet:
all of the above: -the luminosity of its parent star -the mass of a planet -the distance from its parent star -the presence of an atmosphere for the planet
Several versions of the famous Miller-Urey experiment have been carried out to attempt the recreate the initial conditions that may have brought about life on Earth. For these experiments, what was the main type of organic molecule that was created:
amino acids
Kepler expected to find the orbit of Mars fit a perfect circle using the observations of Tycho. Instead, he found that it fit:
an ellipse
In the planetarium you saw an animation of the origin of our moon. The major theory for its origin is also described and shown graphically in the textbook. What is the basis of the theory of the moon's origin:
an impacts of the earth with a giant body about the size of mars
In the future, what is the most likely and simplest way we might detect the presence of life on an extrasolar planet:
analyze the spectrum of reflected light from the planet to look for bio-signatures
Habitability for our purposes of extraterrestrial life generally refers to an environment capable of sustaining:
any kind of life
Extraterrestrial life is defined as:
any kind of life found beyond Earth
The majority of stars on the HR diagram for classifying stars are found to lie on what is called the main sequence. The stars on the main sequence:
are placed with higher mass at higher temperature
Scientists have long searched for planets beyond our solar system. These extrasolar planets:
are planets that have been found orbiting other stars besides the sun
Since the light has a finite speech at which it travels through space, when we observe a distant galaxy that is billions of light years away, we see it:
as it was billions of years ago when the light actually left the galaxy
According to Einstein's Special theory of Relativity, it is not possible to travel:
at or faster than the speech of light
It would be possible to travel great distances and appear to "exceed" the speed of light if instead of just trying to faster, one simply does what:
create a huge distortion in the curvature of local spacetime, thus making the distance to travel shorter
With our current technologies, the biggest challenge to interstellar travel is the huge amount of _______ required in order to accelerate a spaceship to speeds approaching some fraction of the speed of light:
energy
Which of the following is the major domain in the tree of life to which humans belong:
eukaryota (or eukarya)
The expansion of the universe is due to the:
expansion of space between galaxies
The big bang theory for the origin of the universe is supported by Hubble's law for galaxies which in its simplest form states that the more distant a galaxy is from us, the:
faster it is moving away from us
Which of the following would not be considered a possible natural cause of mass extinction for the Earth:
flue like virus invading all species of plants and animals at once
With what other animal species do humans share a common ancestor:
gorillas and chimpanzees
Using radioactive isotopes to date the age of rock is a technique based on the knowledge of the:
half-life of radioactive isotopes
The surface of Venus is much hotter than the surface of the earth because it:
has a very thick atmosphere of carbon dioxide which has created a runaway greenhouse effect
Galileo's observations of Venus showed this planet to go through a phase cycle similar to that of the moon while also changing its angular size. This could only be explained by:
having Venus orbit the sun and not the Earth
How do the surface temperature and atmospheric pressure on Venus compare with the Earth:
higher temperature and higher pressure
In the textbook and in lecture the possibility of evidence for ancient life on Mars from a Martian meteorite (ALH84001) was discussed. What is the most intriguing piece of evidence that suggests that the material of which the meteorite is formed may have once contained life:
highly magnified images of carbonate grains found inside reveal rod-shaped structures that look much like terrestrial fossils of nanobacteria
In addition to outgassing by volcanoes, another important contributor to the formation the Earth's oceans and atmosphere was:
impacts by icy comets and other icy small bodies in the early solar system
Although it is only an approximation, scientist can use the Hubble constant (basically a measure of the rate at which the universe is expanding) to establish a value for what very useful property of the universe:
its age
The discovery of extremophile organisms on earth suggests that:
life elsewhere may be possible over much wider range of conditions that initially thought
What "exploded" during the Cambrian Explosion event around 500 to 600 million years ago?
life, a remarkable growth in animal diversity occurred at that time
According to SETI programs, what would the best way to look for intelligent life elsewhere in the universe:
listen for a radio signal communication coming from space
The HR diagram for classifying stars is a graph of:
luminosity versus temperature
Tycho Brahe was an important character in the history of astronomy because:
made detailed measurements of the positions and motions of the planets in the sky that were much more accurate than any previously thought.
The possibility of the existence of ET life was first considered:
many thousands of years ago by philosophers in ancient cultures
If life does indeed exist elsewhere in our solar system it will most likely take the form of:
microbes or other simple bacteria like life
When you observe planets in the sky at night over a period of months they:
move slowly from west to east relative to the background of stars
In amino acids, every acid has a common structure of an amino group and carboxyl group attached to an "alpha" carbon atom. In the laboratory we created amino acids using model pieces. The carboxyl group obviously includes oxygen within it, but the "amino" group structure is based on an atom of what particular element:
nitrogen
On the basis of the scientific method as we have been emphasizing all semester, which of the following would be considered conclusive physical evidence that we are being visited by an intelligent alien civilization:
none of the above would be conclusive physical evidence
What is the "chicken-and-egg" type problem we face when trying to decide which came first--proteins or nucleic acids:
nucleic acids cannot replicate without proteins, and proteins cannot be made without nucleic acids
The great majority of the extrasolar planets discovered at the present time have been found by:
observation of a periodic dimming of the light from the planet's star due to eclipses by the planet
A most amazing feat was the very first spacecraft landing on a Jovian moon. Cassini carried the Huygens probe to launch to Titan when it visited the Saturn system. When the Huygens probe touched down on Titan after floating by parachute through the atmosphere, it landed:
on a solid surface resembling sand made of frozen ice grains, pebbles and stones resembling a streambed
Given the nebulae with the gas and dust (the basic building blocks of stars and planets) are widespread and the same laws of physics operate everywhere, we would expect:
other solar systems to be somewhat like our own with multiple planets and having rocky type planets closer to the star with gaseous type planets farther away
Cyanobacteria (blue-green algae) are thought to be the primary source for the increase of what gas in our atmosphere that allowed more complex life to develop:
oxygen
Which of the following is NOT a basic requirement for chemically based life:
oxygen from photosynthesis
The field of astrobiology has become more relevant in the past decade because astronomers have gained clear observational evidence that, in addition to the huge number of stars in the universe, there also exists a huge number of:
planets orbiting stars
Which one of the following is not observational evidence that supports the Big Bang Theory for the origin of the universe:
pre-solar nebulae are seen in huge dust and clouds in galaxies
The genetic code in DNA is composed of pairs of only 4 nucleotides. Which one of the following is not a DNA nucleotide base:
proline
which is not an essential requirement for life as we know it:
pure oxygen in breathable form
The climate of the Earth is very sensitive to the "radiation balance" of the atmosphere. This is a balance between:
radiation from the sun entering the atmosphere versus the radiation that the earth sends back into space
Most of the detailed information we know about the planets in our solar system has come from:
robotic spacecraft visits to the planets, both orbiting them and sending down landers
What would be the main potential concerns for human regarding the creation of artificial life in the laboratory:
that such life might be the source of new diseases or toxins for which terrestrial life would have little resistance
According to the REH, it can be argued that:
simple single celled microbial life may be common but complex, multicellular intelligent life is very improbable on any other planet
The main technique that astronomers to use determine the physical and chemical properties of distant stars in the galaxy is:
spectroscopy of light
Which one of the following would not be considered one of the four steps or traits in modern human development:
spiritualism (religious movement)
In our search for stars with habitable planets, we are mostly interested in:
stable, long-lived hydrogen-fusing stars like our sun
Among the great Greek philosophers, Aristotle is recognized for:
stating physical laws and then attempting to use them rather than myths to explain how the universe works
The color index of a star (basically a measure of the color a star appears to be) gives a direct indication of its:
surface temperature
The observational difference between stellar spectral types (i.e., between O, A, B, etc, stars) are caused primarily by difference in the _________ of the stars:
surface temperature
The HR diagram has spectral type on its horizontal axis (OBAFGKM). Which other two properties of a star could be used in place of the spectral type that would yield the same relation for stars on the HR diagram:
temperature or color
Which of the following statements is an overall summary of the findings from the viking lander biology experiments on Mars:
the Martian soil was chemically reactive but showed no "conclusive" signs of biological activity
The observable matter in the universe comes in several different forms, but the main building blocks for creating normal matter are:
the atoms which comprise the elements found in the periodic table
The kepler space telescope mission was the most successful in identifying possible exoplanets. If one combines the light curve information about planet size with the radial velocity information about planet mass, then you can determine a value for which fundamental property of the planet:
the average density of the planet
REH suggests that:
the circumstances that have allowed complex life on earth to appear and develop may be so unique that it is unlikely to have occurred anywhere else
We have discussed the scientific context of the SETL and the overall scientific method. Which one of the following could be explored using the scientific method.
the composition of a rock
The concept of gravity doesn't work for extreme cases (like black holes), Einstein's theory of general relativity is more correct in those cases but he refers to_____________ instead of gravity:
the curvature of spacetime
which one of the following is not a key property of life as we have defined it:
violation of the 2nd law of thermodynamics
In the mars surface lab, you explored the geology of some regions of the surface. What is the relative age of the heavily cratered southern hemisphere highlands of Mars versus the smooth northern plains:
the highlands are older than the plains because they contain larger numbers of impact craters
Our solar system has two major types of planets, these are:
the inner terrestrial planets like Earth and the outer gas giants like Jupiter
Darwin's description of "natural selection" refers to:
the mechanism by which advantageous traits are preferentially passed on from parents to offspring
Newton's laws of motion refer to the change in the velocity or accelerations of an object the results when a force is applied to the object. According to these laws:
the more massive an object is, the smaller its acceleration
The most characteristic feature of the scientific method is:
the mutually supporting, relationship between observations, theory, and prediction.
The process of evolutionary adaptation includes "mutation" whether by some natural or artificial process. What generally happens in a mutation:
the nucleotide base sequence of an organism's DNA is changed
In searching for life in the solar system, which basic requirement of life is the most unlikely to be found and thus the one we always look for:
the presence of liquid water
What is the definition of a star's habitable zone:
the range of distances from the star where liquid water can be stable on the surface of a suitable planet
What is the most important role that nucleic acids (DNA) okay in the cells of living organisms:
the storage and transfer of information
In the context of life in the universe, which of the following discoveries of cosmology suggests that there has been plenty of times for the life to be appeared and evolved elsewhere in the universe:
the universe is very old
Scientific models that are developed to explain the "why" of complex behaviors in nature and that are supported by a large, compelling body of evidence are referred to as:
theories
How do scientists use seismology to learn about the interior of the Earth:
they analyze the seismic waves to determine how fast and through the material they are traveling
Scientists cannot agree on whether viruses are living or not because:
they can only reproduce within a host cell and not independently
The surprising argument of the Fermi Paradox is that if several technologically advanced civilizations exist in our galaxy then:
they should long ago have colonized the entire habitable galaxy yet we find no one else
How is heredity encoded in a DNA molecule:
through genes, a sequence of DNA base pairs
The big bang theory for the origin of the universe leads to the concept of the "spacetime curvature" for the universe as a whole in the following with the ideas expressed by Einstein for General Relativity. Which of the following is "not" a possible curvature description for the universe:
topsy turvy (or inside out)
We discussed in lecture but also viewed emission spectral line patterns from gases in the laboratory. These patterns are:
unique for each element and molecules
Our last lecture introduced the Fermi Paradox, the apparent contradiction between the lack of evidence for extraterrestrial life and various high estimates for its probability. Which one of the following would NOT be considered a solution to the paradox:
we are not interested in and are not searching for alien signals
