Deck 26: Astrobiology: Life on Other Worlds

Question 1

Why are massive main sequence stars not likely to have planets that contain life?

A) The life zones around these stars are too small.
B) These stars would sweep away all of the material from which planets could form.
C) These stars are too hot to allow water to exist as a liquid on any planets that might form.
D) These stars are on the main sequence for too short a time to allow life to evolve.

Answer 1

These stars are on the main sequence for too short a time to allow life to evolve.

Question 2

The "framework" of molecules important for life on Earth is based on _____atoms

A) carbon
B) helium
C) silicon
D) oxygen
E) nitrogen

Answer 2

carbon

Question 3

____ is a segment of a chromosome that controls a specific function.

A) DNA
B) RNA
C) An enzyme
D) A gene
E) An amino acid

Answer 3

A gene

Question 4

The DNA molecule can be altered

A) by chance miscopying of genetic information.
B) by damage from exposure to radioactivity.
C) if the host cell is intelligent and determines that an alteration would help the cell survive.
D) all of the above
E) a and b above

Question 5

The Miller experiment created

A) life.
B) artificial proteins.
C) DNA.
D) simple molds.
E) amino acids.

Question 6

Which of the answers below is NOT a factor in the Drake equation estimating the number of communicative technological civilizations in our galaxy?

A) the number of stars in our galaxy..
B) the fraction of stars with planets
C) the number of suitable planets (with liquid water)per system of planets
D) the fraction of suitable planets on which life arises.
E) the distance of the Earth from our sun.

Question 7

A cell's DNA molecules are constructed of

A) amino acids.
B) proteins.
C) sugars,phosphates,and bases.
D) all of the above
E) none of the above

Question 8

From which of these planets do we have known samples of material?

A) Mercury
B) Venus.
C) Mars
D) All of the above
E) None of the above

Question 9

Current searches for extraterrestrial intelligence use radio telescopes to

A) listen to many stars at the same time at one frequency.
B) listen to many frequencies at the same time.
C) transmit one frequency to many stars at the same time to get replies in a few minutes.
D) transmit many frequencies to one star at the same time to get replies in a few minutes.
E) look for life on Earth.

Question 10

The stars most likely to have inhabited planets are

A) spectral type "G" to "K" main sequence stars.
B) main sequence spectral type "O" stars.
C) protostars
D) neutron stars.
E) black holes

Question 11

Life

A) reproduces itself.
B) contains information necessary for reproduction.
C) both a and b
D) neither a nor b

Question 12

The habitable zone is

A) the region on a planet where conditions are not acceptable for life to exist.
B) a region around a star where a planet has temperatures that permit the existence of liquid water.
C) the visible surface of a star.
D) only found around black holes
E) a region on a young planet where amino acids can begin to form DNA molecules.

Question 13

DNA molecules contain patterns for the production of

A) proteins.
B) enzymes.
C) both a and b
D) neither a nor b

Question 14

The most likely low interference region of the radio spectrum for communication with other civilizations is the water hole,the part of the spectrum

A) at the radio emission of hdrogen in our Galaxy.
B) at the radio emission of OH.
C) at the radio emission of noise from Earth's atmosphere.
D) between the radio emissions of hydrogen and OH.
E) near the radio band where water in the Earth's atmosphere strongly absorbs energy.

Question 15

The processes of life

A) extract energy from the surroundings.
B) maintain the organism.
C) modify the surroundings to promote survival.
D) all of the above

Question 16

The first complex life appeared on Earth about 0.5 billion years ago during the

A) Jurassic Period.
B) Mississippian Period.
C) Cambrian Period.
D) Precambrian Period.
E) Neolithic Period.

Question 17

When estimating the number of technologically advanced civilizations in our Galaxy,it is useful to consider

A) the average life span of an alien.
B) the average life span of the civilization.
C) the distance to the civilization's planet.
D) the type of advanced communication they use.

Question 18

What is important about the habitable zone around a star that makes astronomers believe life could exist there?

A) The level of electromagnetic radiation from the star is zero there.
B) Only on the star's photspheric surface can complex organic molecules be found.
C) Only planets in the habitable zone will have atmospheres.
D) In the habitable zone water can exist as a liquid on the planet.

Question 19

Life on Earth is believed to have begun

A) where only pure liquid water existed
B) where only the element carbon existed
C) Choices"a" and "b" are both wrong! Both liquid water and the element carbon appear to be crucial for life
D) Choices"a" and "b" are both wrong! Both liquid water and the element carbon are totally unimportant in life as we know it.

Question 20

A single human cell encloses about 1.5 meters of DNA containing 4.5 billion base pairs.How far apart are these base pairs in the DNA,in nanometers? [This question requires the use of mathematics.]

A) 3.3*10^-10
B) 3.3*10¹⁰
C) 3*10⁹
D) 300
E) 0.34

Question 21

DNA is coiled into a tight spiral and makes up the ____ that are the genetic material in a cell.

A) genes
B) amino acids
C) enzymes
D) nucleus
E) chromosomes

Question 22

The DNA molecules contain six different bases.

Question 23

____________________ contains the genetic information in human cells.

Question 24

The wavelengths that are most likely for communication with other civilizations are those in the water hole.

Question 25

A change in the genetic information in a cell is called a(n)____________________.

Question 26

Which of the type stars below would be LEAST suitable for life to originate and evolve over several billion years?

A) 0.5 solar mass stars
B) 1.0 solar mass stars
C) 2.0 solar mass stars
D) 20 solar mass stars

Question 27

The Viking spacecraft searched for life on Mars by looking for the effects of life on the upper atmosphere.

Question 28

The Miller experiment created synthetic DNA.

Question 29

Assume we send a space ship to a nearby one solar mass type G main sequence star.As we approach,we see that there are three earth-mass planets circling the star,planet A at 0.4 AU,B at 1.0 AU and C at 5 AU. Which planet would be more likely to have earth type life on its surface?

A) Planet A
B) Planet B
C) Planet C
D) All surfaces would be too hot.
E) All surfaces would be too cold.

Question 30

All life on earth is based on carbon chemistry.

Question 31

DNA molecules cannot be altered by chance errors in reproduction.

Question 32

Even if a society on the nearest start to our Sun survived at a technological level for only 4 years,that is long enough to exchange messages with them.

Question 33

Chemical evolution concentrated the varied smaller molecules into the more stable forms.

Question 34

The Arecibo radio message to extraterrestrials contains information about the structure of DNA.

Question 35

Which of the elements or chemical compounds necessary for life on earth have NOT been identified in meteorites?

A) Hydrogen
B) Oxygen
C) Carbon
D) Amino acids
E) All have been found

Question 36

If life is to develop on a planet,the planet must lie just inside the inner edge of its star's life zone.

Question 37

It is expected that planets around high-mass main sequence stars would be good places to search for extraterrestrial life.

Question 38

____________________ atoms serve as the basis or framework for life on Earth.

Question 39

Suppose we wish to travel to the nearest star using a super space ship capable of traveling at 300 km/s or about one million km/hour or about 26 million km/day or 10 billion km/yr.We have nothing even close to this space ship yet.How long will it take us to get to the nearest star which is about 4 x10¹³ km away from us?

A) 4 years
B) 400 years
C) 4000 years
D) 4 billion years

Question 40

The oldest fossils on Earth are more than 3 billion years old.

Question 41

The most important quantity necessary for life to form appears to be the existence of ____________________ on the surface of the planet.

Question 42

The ____________________ is a means to attempt to calculate the number of communicative civilizations that exist in our galaxy.

Question 43

The portion of the electromagnetic spectrum between the 21-cm line of neutral hydrogen and the 18-cm line of OH is known as the ____________________.

Question 44

The oldest,easily identifiable fossils appear in sedimentary rocks that formed 500 million to 600 million years ago during the ____________________ period.

Question 45

The Miller experiment succeeded in creating ____________________.

Question 46

The ____________________ is a region around a star where liquid water can exist.

Question 47

The failure of improperly adapted life forms to survive versus the survival of properly adapted forms is called ____________________.

Question 48

The Viking landers searched for life on ____________________.