Question 1

In 1974,astronomers sent a message toward globular cluster M13.If life exists there,and it returns our signal,we won't receive it for at least another 44,000 years.Why?

Accepted Answer

A) It will take that long for the space probe carrying our signal to reach the life forms there. 
B) Based on the age of the stars in M13,we anticipate it would take that long for a civilization to evolve enough to interpret and respond to our signal. 
C) M13 is far enough away that even light takes a very long time to reach it. 
D) It will take that long before our Solar System and M13 are properly aligned again. 
E) The universe will have expanded substantially after M13 receives our message,therefore taking much longer for their response to make it back to Earth. 
A) It will take that long for the space probe carrying our signal to reach the life forms there. 
B) Based on the age of the stars in M13,we anticipate it would take that long for a civilization to evolve enough to interpret and respond to our signal. 
C) M13 is far enough away that even light takes a very long time to reach it. 
D) It will take that long before our Solar System and M13 are properly aligned again. 
E) The universe will have expanded substantially after M13 receives our message,therefore taking much longer for their response to make it back to Earth.

Question 2

Name three main dangers (one human and two astrophysical)that threaten the continued existence of human life on Earth.

Accepted Answer

Some examples include the following:
(1)

Question 3

Based on what we know about the evolution of life on Earth,which of the planets below would be most likely to contain an advanced civilization?

Accepted Answer

A) Planet A 
B) Planet B 
C) Planet C 
D) Planet D 
E) Planet E 
A) Planet A 
B) Planet B 
C) Planet C 
D) Planet D 
E) Planet E

Question 4

If future exploration of the moons of Jupiter and Saturn discovered primitive life forms,it would ___________ the probability of finding an advanced civilization somewhere else in the Milky Way because ___________.

Accepted Answer

A) increase;it shows that life can exist in environments which are very different from those found on Earth 
B) increase;it would show that life can survive travel through space after leaving the Earth 
C) not affect;primitive life forms have nothing to do with the existence of advanced civilizations 
D) decrease;it would show that primitive life forms outside the Earth cannot evolve into more complex species 
E) decrease;it would show that primitive life forms are far more common than advanced ones 
A) increase;it shows that life can exist in environments which are very different from those found on Earth 
B) increase;it would show that life can survive travel through space after leaving the Earth 
C) not affect;primitive life forms have nothing to do with the existence of advanced civilizations 
D) decrease;it would show that primitive life forms outside the Earth cannot evolve into more complex species 
E) decrease;it would show that primitive life forms are far more common than advanced ones

Question 5

What would be the number of intelligent civilizations in our galaxy if all stars formed planets,each planet has a 0.1 percent change of supporting life,and every time conditions are right life develops,but only 0.001 percent of the time intelligent life develops,and once it develops it survives indefinitely?

Accepted Answer

The Drake equation says the nu

Question 6

Why was a comet impact 65 million years ago a chance happening that benefited the evolution of humans?

Accepted Answer

A) It deposited a significant amount of nitrogen into the Earth's atmosphere. 
B) It led to an increase in global UV radiation,which killed off most of the forests and jungles. 
C) Mammals got an evolutionary boost. 
D) Plant life began to decline. 
E) It brought human DNA to Earth. 
A) It deposited a significant amount of nitrogen into the Earth's atmosphere. 
B) It led to an increase in global UV radiation,which killed off most of the forests and jungles. 
C) Mammals got an evolutionary boost. 
D) Plant life began to decline. 
E) It brought human DNA to Earth.

Question 7

The Drake equation estimates the number of solar systems in our galaxy today that may harbor life.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following is a likely source of the energy needed to create the first life on Earth?

Accepted Answer

A) land volcanoes 
B) asteroid impacts 
C) lightning 
D) fire 
E) earthquakes 
A) land volcanoes 
B) asteroid impacts 
C) lightning 
D) fire 
E) earthquakes

Question 9

The main goal of the Allen Telescope Array is to search for high redshift galaxies.

Accepted Answer

A) True 
 B)False

Question 10

If we model the history of the universe as a single day,at what time would the first Homo sapiens appear?

Accepted Answer

A) 11:59:58.5 P.M. 
B) 11:59:20 P.M. 
C) 11:35:00 P.M. 
D) 10:00 P.M. 
E) 6:00 P.M. 
A) 11:59:58.5 P.M. 
B) 11:59:20 P.M. 
C) 11:35:00 P.M. 
D) 10:00 P.M. 
E) 6:00 P.M.

Question 11

Animals are most closely related to which of the following branches?

Accepted Answer

A) bacteria 
B) archaea 
C) flagellates 
D) fungi 
E) cyanobacteria 
A) bacteria 
B) archaea 
C) flagellates 
D) fungi 
E) cyanobacteria

Question 12

Which one of the following is NOT one of the six chemical elements commonly found in living organisms?

Accepted Answer

A) helium 
B) hydrogen 
C) oxygen 
D) phosphorus 
E) nitrogen 
A) helium 
B) hydrogen 
C) oxygen 
D) phosphorus 
E) nitrogen

Question 13

Which of the following sketches could describe the evolutionary tree of life on Earth? In each diagram,time increases as you move upward,and each branch represents a different species.

Accepted Answer

A) A 
B) B 
C) C 
D) D 
E) E 
A) A 
B) B 
C) C 
D) D 
E) E

Question 14

SETI's Allen Telescope Array is designed to search ___________ for signs of intelligent life.

Accepted Answer

A) over a thousand stars 
B) over a million stars 
C) over a billion stars 
D) galaxies in the Local Group 
E) the 100 closest spiral galaxies 
A) over a thousand stars 
B) over a million stars 
C) over a billion stars 
D) galaxies in the Local Group 
E) the 100 closest spiral galaxies

Question 15

If you wanted to find intelligent life in the universe,what spectral types of stars would you study and why?

Accepted Answer

It took approximately 4.5 bill

Question 16

People argue against the possibility of time travel by saying,"If humans will eventually be able to travel back in time,then where are all the tourists from the future?" This idea is similar to the ___________,only applied to time travel instead of aliens.

Accepted Answer

A) Drake equation 
B) cosmological principle 
C) Fermi paradox 
D) Urey-Miller experiment 
E) evolutionary tree of life 
A) Drake equation 
B) cosmological principle 
C) Fermi paradox 
D) Urey-Miller experiment 
E) evolutionary tree of life

Question 17

What are the four main elements that make up all living organisms on the Earth?

Accepted Answer

CHON: carb

Question 18

Mutations always lead to improvements in an organism's ability to survive and reproduce.

Accepted Answer

A) True 
 B)False

Question 19

Describe the experiment depicted below.What was the goal of the experiment? Was the experiment a success?

Accepted Answer

This image shows the Urey-Miller experim

Question 20

Why did the presence of cyanobacteria on Earth in the past allow humans to exist?

Accepted Answer

A) It was the first form of life. 
B) It oxygenated the atmosphere. 
C) It fertilized the soil to let plants grow. 
D) It increased the carbon dioxide in the atmosphere,causing the greenhouse effect. 
E) It was the first life form based on DNA. 
A) It was the first form of life. 
B) It oxygenated the atmosphere. 
C) It fertilized the soil to let plants grow. 
D) It increased the carbon dioxide in the atmosphere,causing the greenhouse effect. 
E) It was the first life form based on DNA.

Exam 24: Life

In 1974,astronomers sent a message toward globular cluster M13.If life exists there,and it returns our signal,we won't receive it for at least another 44,000 years.Why?

Name three main dangers (one human and two astrophysical)that threaten the continued existence of human life on Earth.

Based on what we know about the evolution of life on Earth,which of the planets below would be most likely to contain an advanced civilization?

If future exploration of the moons of Jupiter and Saturn discovered primitive life forms,it would ___________ the probability of finding an advanced civilization somewhere else in the Milky Way because ___________.

Why was a comet impact 65 million years ago a chance happening that benefited the evolution of humans?

The Drake equation estimates the number of solar systems in our galaxy today that may harbor life.

Which of the following is a likely source of the energy needed to create the first life on Earth?

The main goal of the Allen Telescope Array is to search for high redshift galaxies.

If we model the history of the universe as a single day,at what time would the first Homo sapiens appear?

Animals are most closely related to which of the following branches?

Which one of the following is NOT one of the six chemical elements commonly found in living organisms?

Which of the following sketches could describe the evolutionary tree of life on Earth? In each diagram,time increases as you move upward,and each branch represents a different species.

SETI's Allen Telescope Array is designed to search ___________ for signs of intelligent life.

If you wanted to find intelligent life in the universe,what spectral types of stars would you study and why?

People argue against the possibility of time travel by saying,"If humans will eventually be able to travel back in time,then where are all the tourists from the future?" This idea is similar to the ___________,only applied to time travel instead of aliens.

What are the four main elements that make up all living organisms on the Earth?

Mutations always lead to improvements in an organism's ability to survive and reproduce.

Describe the experiment depicted below.What was the goal of the experiment? Was the experiment a success?

Why did the presence of cyanobacteria on Earth in the past allow humans to exist?

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornments Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Filters

If future exploration of the moons of Jupiter and Saturn discovered primitive life forms,it would _ the probability of finding an advanced civilization somewhere else in the Milky Way because _.