Deck 18: Life in the Universe

Question 1

Which one of the following is NOT one of the three categories of terrestrial life based on its DNA characteristics?

A) bacteria
B) Eukarya
C) Archaea
D) fungi

Answer 1

fungi

Question 2

Humans belong to which branch of the phylogenetic tree of life?

A) Archaea
B) bacteria
C) Eukarya
D) fungi

Answer 2

Eukarya

Question 3

The phylogenetic tree of life was established using:

A) bacteria.
B) DNA sequencing.
C) fossils.
D) fungi.

Answer 3

DNA sequencing.

Question 4

Life in the universe could form:

A) after the Big Bang.
B) before the Big Bang.
C) during the Big Bang.
D) We have no way of predicting.

Question 5

What occurred approximately 500 million years ago?

A) the extinction of the dinosaurs
B) the Cambrian explosion
C) the rise of mammals
D) the birth of the first humans

Question 6

Complex microorganisms that have complex DNA enclosed in a cell nucleus are called:

A) algae.
B) bacteria.
C) eukaryotes.
D) prokaryotes.

Question 7

All terrestrial life is ________-based.

A) carbon
B) hydrogen
C) nitrogen
D) oxygen

Question 8

Which of the following is the study of the origin,evolution,distribution,and future of life in the universe?

A) astrobiology
B) biology
C) cosmology
D) physiology

Question 9

If we model the history of Earth as a single day,at what time would the first primitive forms of microorganisms appear?

A) 5:00 A.M.
B) 9:00 A.M.
C) 12:00 noon
D) 3:00 P.M.

Question 10

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

A) It deposited a significant amount of nitrogen into 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.

Question 11

Terrestrial life is carbon-based and requires ________ as its solvent.

A) carbon
B) DNA
C) hydrogen
D) liquid water

Question 12

Venus and Mars have little free oxygen in their atmospheres.What has allowed Earth to have a large amount of oxygen in its atmosphere?

A) bombardment
B) cyanobacteria and other photosynthesizing organisms
C) volcanism
D) water on Earth's surface

Question 13

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

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

Question 14

If we model the history of Earth as a single day,at what time would the first human civilizations appear?

A) 0.2 seconds before midnight
B) 2 minutes before midnight
C) 10:00 P.M.
D) 6:00 P.M.

Question 15

The early Earth suffered a long period of bombardment.With respect to this time period,when did life arise and evolve?

A) after bombardment
B) before bombardment
C) during bombardment
D) We have no way of predicting.

Question 16

We search for intelligent life in the universe by:

A) sending out spacecraft with messages on them.
B) using radio telescopes to search for radio signals.
C) monitoring ultraviolet radiation emitted by stars.
D) all of the above

Question 17

In 1952,chemists Harold Urey and Stanley Miller mixed ammonia,methane,and hydrogen in a closed container,zapped it with electrical sparks,and found that:

A) they could induce cold fusion to occur.
B) they could not induce any amino acids to form.
C) single-celled microorganisms had been spontaneously created.
D) they had created about half the amino acids that form proteins.

Question 18

Where do we think life first formed on Earth?

A) in the air
B) in the oceans
C) on land
D) on asteroids that carried microorganisms to Earth

Question 19

If we model the age of the universe as a single day,at what time would the earliest traces of humanity appear on Earth?

A) 11:00:00 P.M.
B) 11:35:00 P.M.
C) 11:53:10 P.M.
D) 11:59:25 P.M.

Question 20

Which of the following appeared most recently in Earth's evolutionary timeline?

A) dinosaurs
B) forests
C) humans
D) insects

Question 21

Carbon forms the backbone of our DNA because:

A) it is the most abundant element in the universe after hydrogen and helium.
B) it reacts easily with oxygen.
C) it remains solid even at high temperatures.
D) a carbon atom can bond with up to four atoms at a time.

Question 22

A value of N = 0.1 for the Drake equation signifies that:

A) 1 of every 10 solar systems in our galaxy harbors intelligent life.
B) 1 of every 10 solar systems in our galaxy harbors life of some kind.
C) 1 of every 10 galaxies in our universe harbors intelligent life.
D) 1 of every 10 galaxies in our universe harbors life of some kind.

Question 23

What is the goal of SETI?

A) to communicate with alien life
B) to discover alien life of any form
C) to discover extraterrestrial civilizations
D) to protect Earth from aliens

Question 24

The habitable zone around a star depends most on its:

A) mass and age.
B) radius and distance.
C) color and distance.
D) luminosity and velocity.

Question 25

As the Sun evolves into a red giant,what will happen to the location of the habitable zone in our Solar System?

A) move away from the Sun
B) move closer to the Sun
C) remain in its current position
D) We have no way of predicting.

Question 26

NASA spacecraft have found good evidence that liquid water in large amounts previously existed on the surface of:

A) Mars.
B) Mercury.
C) Titan.
D) Venus.

Question 27

Based on what you know of Earth's evolution,what percentage of Earth-like planets in a star cluster with an age of 2 billion years has intelligent life?

A) 0 percent
B) 10 percent
C) 30 percent
D) 50 percent

Question 28

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

A) more than a thousand stars
B) more than a million stars
C) galaxies in the Local Group
D) the 100 closest spiral galaxies

Question 29

What does it mean if a population demonstrates exponential growth?

A) Population decreases to zero.
B) Population increases by a fixed amount in each given time interval.
C) Population increases by a percentage in each given time interval.
D) There is no such thing as exponential growth.

Question 30

All of the following events will likely occur in the future.Which would require that humanity leaves the Solar System to survive?

A) asteroid or cometary impact on Earth
B) continuation of global climate change on Earth
C) evolution of the Sun into a red giant
D) overuse of natural resources on Earth

Question 31

Why is it unlikely that we will ever contact extraterrestrial life? Choose the most correct answer.

A) Aliens have already contacted us.
B) Life is unlikely to exist elsewhere in the universe.
C) Our technology does not allow us to pick up signals.
D) Space is very big.

Question 32

Evidence for lakes of hydrocarbons,such as methane,has been discovered on:

A) Mars.
B) Mercury.
C) Titan.
D) Venus.

Question 33

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 48,000 years.Why not?

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.

Question 34

Why is a very hot star not a good candidate to find life?

A) The star is too hot.
B) Hot stars are only found in the disk of the galaxy, which is not conducive to life.
C) Its lifetime is too short for life to evolve.
D) The elements that are around hot stars do not lead to evolution.

Question 35

Why is a cold star not a good candidate to find life?

A) The star is too cold.
B) The habitable zone is very narrow.
C) Its lifetime is too long for life to evolve.
D) The elements that are around cold stars do not lead to evolution.

Question 36

As the Sun evolves into a red giant,where will we need to move to within our Solar System if humanity still exists?

A) Mars
B) Mercury
C) our Moon
D) the moons of the outer planets

Question 37

Which of the following elements is so similar to carbon it its structure that scientists think it may form a basis for life elsewhere.

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

Question 38

The Drake equation is used to predict the number of:

A) civilizations in the Milky Way Galaxy.
B) Earth-like planets in the Milky Way Galaxy.
C) planets in the Milky Way Galaxy.
D) planets with life in the Milky Way Galaxy.

Question 39

Why does a planet's size matter when predicting if it can support life?

A) Gravity will determine if a planet can retain an atmosphere.
B) Large worlds are most likely to have life based on our own Solar System.
C) Only very large worlds have atmospheres.
D) Water only exists on very large planets.

Question 40

If the most pessimistic assumptions in the Drake equation were true,we would:

A) have to wait for approximately 60 million years to get a message back from the nearest intelligent life.
B) have to wait for approximately 400 years to get a message back from the nearest intelligent life.
C) be the only intelligent life in the universe.
D) need to concentrate on the Andromeda Galaxy when searching for intelligent life.

Question 41

Describe the difference between prokaryotes and eukaryotes.

Question 42

Describe the experiments of Harold Urey and Stanley Miller in understanding the origins of life.

Question 43

Given the following information,what would be the number of intelligent civilizations in our galaxy? If all stars formed planets; each planet has an 0.1 percent chance of supporting life; every time conditions are right,life develops; and only 0.001 percent of the time,intelligent life develops surviving indefinitely.

Question 44

What is SETI,what is its main objective,and how does it plan to achieve its objective?

Question 45

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

Question 46

Explain the roles of mutations and heredity in biological evolution.

Question 47

If the entire history of Earth were scaled to fit into 1 day,what time of day would microorganisms first form,oxygen start becoming a significant component of the atmosphere,and humans split off from their genetic ancestors?

Question 48

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

Question 49

Describe what is meant by "galactic habitable zone."

Question 50

Scientists have shown that ammonia and methane,mixed together with hydrogen,carbon dioxide,or nitrogen,can produce some of the amino acids essential for life.What else is necessary in this process and why?

Question 51

What determines whether or not a specific mutation is passed on to future generations?

Question 52

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

Question 53

Why would the 21-cm line be a good place to search for signals from intelligent life in the universe?

Question 54

Make an argument in support of the following statement: "The earliest forms of life on Earth must have been extremophiles."

Question 55

Calculate the maximum likelihood that any technically advanced civilization that arose still exists in our galaxy today.