Question 1

Which of the following appears most favored by natural selection?

Accepted Answer

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

Question 2

What is an organic molecule based on? Why?

Accepted Answer

Carbon atoms. They can form th

Question 3

What is meant by the "habitable zone"?

Accepted Answer

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 
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 4

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

Accepted Answer

A) True 
 B)False

Question 5

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:

Accepted Answer

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. 
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 6

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

Accepted Answer

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

Question 7

In the habitable zone, surface water must be at least partially ________ in phase.

Accepted Answer

The answer of In the habitable zone, surface water must...

Question 8

Would N be higher or lower in an elliptical galaxy? Explain.

Accepted Answer

Much lower, for star formation ceased lo

Question 9

What is meant by the idea life on Earth had an "interstellar origin"?

Accepted Answer

Organic molecules have been found in com

Question 10

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

Accepted Answer

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 
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 11

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

Accepted Answer

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

Question 12

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

Accepted Answer

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. 
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 13

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

Accepted Answer

A) True 
 B)False

Question 14

Why is Earth a stronger radio emitter than the Sun?

Accepted Answer

Since many commercial FM radio

Question 15

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

Accepted Answer

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. 
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 16

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

Accepted Answer

A) True 
 B)False

Question 17

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

Accepted Answer

The answer of Life on Earth remained single celled for...

Question 18

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

Accepted Answer

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

Question 19

The Drake equation calculates N. What is N?

Accepted Answer

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 
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 20

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

Accepted Answer

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. 
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.

Exam 28: Life in the Universe: Are We Alone

Which of the following appears most favored by natural selection?

What is an organic molecule based on? Why?

What is meant by the "habitable zone"?

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

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:

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

In the habitable zone, surface water must be at least partially ________ in phase.

Would N be higher or lower in an elliptical galaxy? Explain.

What is meant by the idea life on Earth had an "interstellar origin"?

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

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

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

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

Why is Earth a stronger radio emitter than the Sun?

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

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

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

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

The Drake equation calculates N. What is N?

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

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information From the Cosmos

Spectroscopy: the Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earths Sister Planet

Mars: a Near Miss for Life

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants, Dwarfs, and the Main Sequence

The Interstellar Medium: Gas and Dust Among the Stars

Star Formation: a Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae, Supernovae, and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: a Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

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