Deck 28: Life in the Universe: Are We Alone

Question 1

Comets were likely a major agent in bringing both water and organic molecules to the surfaceof the early Earth.

Answer 1

True

Question 2

Organic molecules can only be made by living things.

Answer 2

False

Question 3

Life emerged on Earth about a billion years after the solar system formed.

Answer 3

True

Question 4

Life is thought to be unlikely in subsurface oceans, such as those in Europa, because sunlightdoes not reach these oceans.

Question 5

NASA has found definite proof for the past existence of life on Mars.

Question 6

Elliptical galaxies, with older stars, will be more likely to have evolved intelligences than thestars close to us in the Milky Way.

Question 7

Some meteorites that survive the plunge to Earth's surface contain organic compounds.

Question 8

We now know that photosynthesis is not the only energy mechanism that life can use tosupply it with energy.

Question 9

Each factor in the Drake Equation has a well-known, established value.

Question 10

Earth behaves as an artificial pulsar, with the strongest pulses for alien observers when NorthAmerica is either rising or setting.

Question 11

As yet, no human probe has completely left our solar system and gone into interstellar space.

Question 12

We have found Titan's surface to have perfect living conditions for earthlike life.

Question 13

An F-type star would have a larger habitable zone than does our Sun.

Question 14

Of the terrestrial planets, Mars seems to be most promising to exobiologists.

Question 15

Of the billions of possible combinations of atoms into organic molecules, only about 1500actually occur.

Question 16

Comet impacts might have been a good mechanism for seeding the hot early Earth with thewater and molecules of life.

Question 17

Due to the first strong commercial radio stations, our radio presence is now known out toover about 70 light-years.

Question 18

Europa is the most promising of the bodies in the outer solar system for life in its salty seas.

Question 19

The radio signals from Earth are greater than from the Sun.

Question 20

Hundreds of complex organic molecules exist in deep space, especially in the giant molecularclouds.

Question 21

Which of the following appears most favored by natural selection?

A)intelligence
B)opposable thumbs
C)bipedal locomotion
D)binocular vision
E)live birth

Question 22

During which step in cosmic evolution were the chemical bases for life created?

A)particulate evolution
B)stellar evolution
C)chemical evolution
D)biological evolution
E)cultural evolution

Question 23

For which of these forms of life is it hardest to apply present criteria for life, based on itsbehavior when isolated?

A)a bacterial spore
B)a plant seed
C)a virus
D)a fungus spore
E)a slime mold

Question 24

What important molecules of life did Miller and Urey brew up?

A)RNA
B)fatty acids
C)lean acids
D)amino acids
E)antacids

Question 25

Why is the hypothesis that life on Earth came from outer space considered plausible?

A)because alien DNA is like human DNA
B)because organic molecules have been found in space
C)because many meteorites contain complex organic molecules
D)because Earth has had many collisions in its history
E)because Earth formed with the Sun from the solar nebula

Question 26

If the material for life were introduced from space after the Earth formed, a major carrierwould have been:

A)the solar wind.
B)tektites from the Moon.
C)comet impacts.
D)encounters with other solar systems.
E)iron meteorites.

Question 27

The famed meteorite with carbonate rocks and possible microfossils came from:

A)Venus.
B)the Moon.
C)Mars.
D)Europa.
E)Comet Halley.

Question 28

The last step in cosmic evolution is:

A)particulate evolution.
B)stellar evolution.
C)chemical evolution.
D)biological evolution.
E)cultural evolution.

Question 29

What unusual discovery was made about the Murchison Meteorite?

A)It is from Mars.
B)It contains iron.
C)It contains living cells.
D)It contains amino acids.
E)It is the largest known meteorite.

Question 30

How long ago did multicellular life forms appear in the fossil record?

A)4.5 billion years ago
B)3.8 billion years ago
C)one billion years ago
D)63 million years ago
E)30 million years ago

Question 31

The water hole is a region around Sun-like stars where liquid water can exist on the surfacesof terrestrial planets.

Question 32

The unusual nature of viruses (behaving as living organisms while within them, butbecoming inert while isolated)has caused scientists to consider the possibility that:

A)viruses may be considered a kind of life.
B)the ability to breathe may need to be added to the definition of life.
C)the ability to evolve or mutate should be added to the definition of life.
D)the ability to grow should be added to the definition of life.
E)the definition of life may be more complex than a simple checklist.

Question 33

Organic molecules are:

A)living cells.
B)carbon-based.
C)silicon-based.
D)found only on Earth.
E)not found outside our solar system.

Question 34

Large molecules found in meteorites and interstellar clouds is evidence that:

A)life is abundant in the galaxy.
B)life has definitely formed in other places than Earth.
C)chemical evolution has taken place elsewhere in the Universe.
D)organic molecules are extremely rare.
E)life originated on Mars before Earth.

Question 35

The first step in cosmic evolution is:

A)particulate evolution.
B)stellar evolution.
C)chemical evolution.
D)biological evolution.
E)cultural evolution.

Question 36

During which step in cosmic evolution did diverse life forms begin to arise?

A)particulate evolution
B)stellar evolution
C)chemical evolution
D)biological evolution
E)cultural evolution

Question 37

The simplest life forms appeared on Earth when it was how old?

A)five million years
B)one billion years
C)2.5 billion years
D)3.5 billion years
E)4.5 billion years

Question 38

How long between the evolution of single versus multicellular organisms?

A)4.5 billion years
B)2.5 billion years
C)one billion years
D)600 million years
E)63 million years

Question 39

Which type of molecules, vital to our life, was found in Murchison and similar carbonaceouschondrites?

A)amino acids
B)DNA
C)lipids
D)sugars
E)vitamins

Question 40

Which of the following does NOT reveal information about conditions on the early Earth?

A)the fossil record
B)the sedimentary rocks found on the most ancient exposures in Greenland
C)laboratory simulations of the primordial ocean and atmosphere
D)advanced experiments on amino acids
E)evidence gleaned from other planets in the early stages of their evolution

Question 41

An experiment was done where a "primordial soup" of water, methane, carbon dioxide andammonia was electrified. Following this, the material was found to contain many of the aminoacids found in all living things on Earth. The purpose of this experiment was to:

A)determine whether DNA could have formed from electrolysis.
B)determine whether DNA could have formed from amino acids.
C)determine whether DNA could have formed from water and methane.
D)determine whether amino acids could have formed naturally on Earth.
E)determine whether amino acids could have formed from water, methane, carbon dioxide andammonia.

Question 42

According to our definition, we have been a technological civilization for about:

A)1000 years.
B)10,000 years.
C)100 years.
D)10 years.
E)500 years.

Question 43

What was detected on Halley's Comet and observed on Hale-Bopp that implied thepossibility of life on Earth originating in space?

A)DNA
B)amino acids
C)organic material
D)nucleotide bases
E)ammonia

Question 44

An experiment similar to the Miller-Urey Experiment was more recently done by NASAusing an icy mixture of water, methanol, ammonia and carbon monoxide. The mixture wasexposed to ultraviolet radiation. The results of this experiment were that no amino acids or DNAwas formed, but complex organic molecules were observed. The purpose of this experiment wasto determine whether:

A)DNA could form from amino acids.
B)DNA could form from ultraviolet radiation.
C)ultraviolet radiation could create amino acids.
D)amino acids could form in the harsh vacuum of outer space.
E)amino acids could form from water, methanol, ammonia and carbon monoxide.

Question 45

Some scientists believe that silicon-based life is possible because:

A)such life was featured on an episode of Star Trek.
B)extremophiles found in thermal vents on Earth are based on silicon.
C)silicon is a key element in computer technology, and computers can nearly imitate intelligentlife.
D)silicon compounds are soluble in ammonia.
E)silicon is chemically similar to carbon.

Question 46

In terms of its thick and chemically active atmosphere of hydrocarbons, which jovian moonwas visited by the Huygens probe in 2005?

A)Europa
B)Triton
C)Titan
D)Titania
E)Enceladus

Question 47

How does Drake define a technological civilization?

A)one that can get into space
B)one that can communicate over interstellar distances
C)one that has a written language
D)one that can construct metal tools
E)one that can have the intelligence not to destroy itself

Question 48

What other recent hypotheses would corroborate the hypothesis that life on Earth originatedin space? (Choose all that apply.)

A)amino acids forming DNA
B)meteorites containing amino acids
C)cometary impacts as the source of water on Earth
D)early aerobic organisms created the oxygen in Earth's atmosphere
E)the fossil record showing how biological organisms on Earth have changed over time

Question 49

What is meant by the "habitable zone"?

A)the zone where water can be a liquid around the center of the Galaxy
B)the region around each star where terrestrial planets could have liquid water on their surfaces
C)the zone in which terrestrial-sized planets could form around each star
D)the region in dense atmospheres like Jupiter's that water droplets could form
E)the regions near the poles of Mercury where liquid water might exist

Question 50

Which type of star would have the largest habitable zone?

A)O5V
B)F5V
C)M5V
D)K5II
E)white dwarf

Question 51

What do Viking, Pathfinder, and the two Mars Rovers have in common?

A)They all found proof of life on Mars.
B)They all could move over the surface of Mars to examine the rocks.
C)They all were designed to investigate Mars' potential for life.
D)They all are still transmitting data from Mars to Earth.
E)They all proved Mars was too inhospitable for life to have ever existed there.

Question 52

Assuming the conditions ripe for life and intelligence abound in the Galaxy, what factorlimits the number of galactic civilizations?

A)the lack of metals for technology
B)the number of supernova explosions
C)the expansion of the Universe
D)the average survival time of the civilizations
E)the speed of technological development

Question 53

Which four moons of the jovian planets show the most promise of life?

A)Io, Ganymede, Callisto, Europa
B)Titan, Enceladus, Dione, Mimas
C)Miranda, Titania, Ariel, Oberon
D)Enceladus, Europa, Ganymede, Titan
E)Ganymede, Titan, Miranda, Enceladus

Question 54

In addition to Mars, which jovian moon shows some promise of life, with a surface not thatdifferent from the Arctic Ocean?

A)Titan
B)Miranda
C)Europa
D)Io
E)Triton

Question 55

Of all the chemical elements, the one most crucial to the complexity of life is:

A)hydrogen.
B)oxygen.
C)sulfur.
D)carbon.
E)nitrogen.

Question 56

Which of these does Mars NOT have to help its case of past or present life?

A)occasional water flows, and past records of much larger ones
B)a protective ozone layer
C)carbon dioxide to provide some greenhouse warming
D)a favorable distance from the Sun
E)rover discoveries of sedimentary rocks and carbonates on the surface of Mars

Question 57

If we are optimistic in our assumptions about the development of life and intelligence, thenthe number of technological civilizations in the galaxy should equal the:

A)average lifetime of a civilization.
B)number of stars forming per year.
C)average number of planets per star.
D)number of stars in the galaxy's habitable zone.
E)average number of planets that produce life.

Question 58

Recently discovered organisms that create their energy through chemical reactions(chemosynthesis instead of photosynthesis)and live in environments previously thought tooalkaline, hot, cold, dark, saline, etc. to sustain life. These organisms are collectively called:

A)viruses.
B)huge crabs.
C)extremophiles.
D)hydrothermal vents.
E)giant red tubeworms.

Question 59

Choose the list that is correct in order of size from largest to smallest.

A)amino acids, genes, carbon dioxide, DNA
B)genes, amino acids, DNA, carbon dioxide
C)carbon dioxide, amino acids, genes, DNA
D)DNA, genes, amino acids, carbon dioxide
E)DNA, genes, carbon dioxide, amino acids

Question 60

Why do we feel type O and B stars are poor candidates for extraterrestrial life?

A)They do not have a habitable Zone.
B)They don't produce enough yellow light.
C)Their lifetime is too short.
D)They don't produce a planetary system.
E)Their habitable zone lies too close to the star.

Question 61

The ________ habitable zone is set by the activity of the nucleus on the inside, and the rate ofstar formation and proper chemistry on the outside.

Question 62

In addition to the proper chemistry, it is ________ that determines the feasibility of life on agiven planet.

Question 63

Which of these radio waves would fall in the "water hole"?

A)15,000 cm wavelength
B)6.563 cm wavelength
C)19 cm wavelength
D)150 cm wavelength
E)243 cm wavelength

Question 64

As a radio source, the period of "pulsar Earth" is:

A)30 minutes.
B)23 hours, 56 minutes.
C)24 hours.
D)29.5 days.
E)365.25 days.

Question 65

Evidence gathered from observations of exoplanets indicates approximately what percentageof stars has planets?

A)0
B)1
C)10
D)100
E)It is not yet possible to make an estimate.

Question 66

Conducted in 1953, the ________ experiments were designed to show what types of complexmolecules might have formed in the Earth's primitive environment.

Question 67

Most SETI searches are done at:

A)X-ray wavelengths.
B)infrared wavelengths.
C)visual wavelengths.
D)radio wavelengths.
E)gamma wavelengths.

Question 68

The Drake equation calculates N. What is N?

A)the number of intelligences in the entire universe
B)the number of technical civilizations in our galaxy presently
C)the number of stars with habitable planets
D)the number of planets with life in the universe
E)the number of planets in just our galaxy

Question 69

The first probe carrying humanity's message to alien civilizations was:

A)Sputnik I.
B)Mariner 4.
C)Pioneer 10.
D)Voyager I.
E)New Horizons.

Question 70

Life on Earth remained single celled for ________ years, according to the microfossil record.

Question 71

The Drake equation now tells us that the number of technological civilizations in our Galaxyat this time is:

A)only our own.
B)five to ten at most.
C)perhaps 3,000.
D)millions.
E)not known; insufficient data to compute.

Question 72

Taking the total number of stars in the Milky Way and dividing by the age of the Milky Wayis a way to estimate:

A)the age of the stars in the Milky Way.
B)the star formation rate in the Milky Way.
C)the average age of a star in the Milky Way.
D)the rate of formation of high mass stars in the Milky Way.
E)the average age of a low mass main sequence star in the Milky Way.

Question 73

Of the planetary systems that may exist in our galaxy, what fraction may contain a habitableplanet?

A)almost all
B)about half
C)about a tenth
D)only 1 in 50
E)less than 1 in 100

Question 74

Our earliest atmosphere, formed by outgassing, was much poorer in ________ than now.

Question 75

According to the parameters derived for the Drake Equation, where should astronomers lookfor life in the Milky Way?

A)around F, G, or M stars that are in multiple star systems located in the galactic habitable zonewith a multiple planet system with jovian outer planets and at least one terrestrial planet withinthe star's habitable zone
B)around O, B, or A stars that are in single star systems located in the galactic nucleus with amultiple planet system with jovian outer planets and at least one terrestrial planet within the star'shabitable zone
C)around F, G, or M stars that are in single star systems located in the galactic habitable zonewith a multiple planet system with jovian outer planets and at least one terrestrial planet withinthe star's habitable zone
D)around O, B, or A stars that are in single star systems located in the galactic habitable zonewith a multiple planet system with jovian outer planets and at least one terrestrial planet withinthe star's habitable zone
E)around F, G, or M stars that are in single star systems located in the galactic habitable zonewith a multiple planet system with no outer planets and at least one terrestrial planet within thestar's habitable zone

Question 76

An extraterrestrial observer would pick up the strongest radio signals when:

A)the Earth was at perihelion.
B)North America was either rising or setting for the observer.
C)North America was directly in front of the observers.
D)at new or full Moon.
E)Saturday Night Live is on.

Question 77

Which of these technological advances would make it harder for extraterrestrial life to findus?

A)FM radio
B)color television
C)the Global Positioning Satellite Network
D)cable TV
E)geosynchronous satellites

Question 78

Considering both longevity and luminosity, which of these stars would be the most likelycandidate for seeking extraterrestrial intelligence?

A)Spica, a B3 main sequence star
B)61 Cygni, a K2 main sequence star
C)Sirius B, a white dwarf
D)Antares, a M3 supergiant
E)Barnard's star, a M5 dwarf

Question 79

How is a technical civilization defined?

A)a civilization that can avoid self-destruction for long periods
B)a civilization that can communicate over interstellar distances
C)a civilization that has the ability to store and process information
D)a civilization that has developed interplanetary space travel
E)a civilization that can construct tools out of raw materials

Question 80

To date, our serious searches for extraterrestrial life have been done almost entirely:

A)in Roswell and Gulf Breeze.
B)with radio telescopes.
C)with optical telescopes looking for nuclear tests.
D)with microwaves in the giant molecular clouds.
E)with infrared telescopes looking for greenhouse gases.