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NATS 1880 Midterm > NATS 1880 Midterm Review > Flashcards

NATS 1880 Midterm Review Flashcards

1
Q

A habitable world is defined to be one that

A

has surface conditions similar to Earth’s and thus suitable for life

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2
Q

What would be an obvious advantage in searching for extraterrestrial life in our Solar System as opposed to on planets around another star?

A

We can physically search for life on planets or satellites in our Solar System

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3
Q

Which statement is incorrect.

A

Based upon the multitude of planets with life found so far, we can conclude that the principles of biology are universal.

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4
Q

Among the other planets in our own Solar System, probably the most likely place to find evidence for life that may exist now or may have existed in the past is on

A

Mars

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5
Q

Astronomy has shown us that the Earth

A

is just one planet orbiting an ordinary star in a vast universe

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6
Q

During the latter half of the twentieth century, astronomers and planetary scientists predicted that planets around other stars should be

A

common

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7
Q

Extraterrestrial life elsewhere in the universe

A

could be similar to life on Earth or might be completely different

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8
Q

Extraterrestrial life is defined to be

A

any kind of life found beyond the Earth

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9
Q

For most of human history it was believed that Earth was, erroneously, at the center of the Universe. This idea is referred to as

A

geocentric

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10
Q

The physics experiment conducted by astronauts on the Moon as discussed in class

A

verified that objects of different mass fall at the same rate in a gravity field as proposed by Galileo

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11
Q

Based upon our preliminary discussions of where life may be found in our Solar System, which of the following locations is considered least likely to harbour life?

A

Mercury

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12
Q

A basic definition for astrobiology is

A

the merger of astronomy and biology to find life beyond Earth

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13
Q

Beneath the surface or which moon of Jupiter is there the strongest evidence for the existence of a subsurface ocean of liquid water?

A

Europa

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14
Q

Biologists have found that life on Earth can

A

survive over a wide range of environmental conditions

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15
Q

While planets in our Solar System have been observed since the dawn of time, exoplanets are by comparison a recent discovery. Approximately when was the first exoplanet discovered?

A

Mid 1990s

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16
Q

Planets orbiting around stars other than our Sun are known as

A

extrasolar or exoplanets

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17
Q

Possible evidence for subsurface liquids has been found beneath the surfaces of one or more of the moons of

A

Jupiter, Saturn, and Neptune

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18
Q

Astronomers have observational evidence that, in addition to being full of stars, our galaxy is also full of

A

Planets

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19
Q

The fact that the life on Earth appeared shortly after its formation (~600 million years or so) suggests that life

A

could arise on most habitable worlds

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20
Q

The molecular building blocks of life have been found

A

on the Earth, in interstellar clouds, and in meteorites

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21
Q

The portrayal of nearly all aliens in movies and on TV as being humanoid is

A

probably unrealistic because the human form is most likely a result of the particular conditions and events that occurred on the Earth

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22
Q

The Search for Extraterrestrial Intelligence (SETI) program primarily involves

A

listening for radio signals broadcast by advanced civilizations

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23
Q

The search for life in the universe

A

is influenced by almost every other branch of science

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24
Q

Assuming current spacecraft speeds (e.g. Voyager), approximately how long would it take to reach the nearest stars (a few light years away)?

A

tens of thousands of years

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25
Q

Given the technological advances of recent years, astronomers are confident that we will probably be

A

able to detect the spectral signatures of life on planets and moons around other stars

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26
Q

The discussion of whether life exists elsewhere in the universe has

A

been a topic of great interest to humans for literally thousands of years

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27
Q

Which statement best characterizes the scientific community’s current understanding about life in the universe?

A

With the exception of life on Earth, no life elsewhere has yet been identified

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28
Q

Life on Earth exists in a multitude of forms. When humans search for life beyond our planet, we are looking for

A

any form of life that has similar characteristics to Earth based life (life we could recognize)

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29
Q

Astronomy has shown us that the fundamental laws of physics are

A

the same everywhere in the universe

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30
Q

Astronomical research now allows us to conclude that

A

the amount of real estate (planets) on which life may exist likely very large

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31
Q

Astrology and the creation of a “Horoscope” would be considered to violate the scientific method because

A

the “predictions’ that are made are rarely specific and cannot be repeated and thus verified

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32
Q

Which statement is correct? (2.1)

A

Brahe was arguably one of the best observational astronomers of the pre-telescopic era

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33
Q

The notion of the Celestial Sphere was first proposed by

A

Anaximander

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34
Q

What evidence did not challenge the Geocentric Model of the Solar System?

A

Retrograde motion of the planets.

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35
Q

In a Sun centred Solar System

A

all planets orbit the Sun which is at the centre of the solar system

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36
Q

A comet orbits the Sun with a semi-major axis of 9 A.U. What is its orbital period?

A

27 years

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37
Q

As you observe stars that are increasingly further from Earth

A

The parallax angle decreases

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38
Q

Which statement is correct? (2.2)

A

Planets normally moved eastwards across the celestial sphere

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39
Q

What is the correct sequence involved in the scientific method?

A

Observe, hypothesis, predict, test, iterate

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40
Q

From Toronto in the winter the Sun rises in the

A

east

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41
Q

Observations of a lunar eclipse led some early scientists to conclude

A

that the Earth was round based upon the appearance of its shadow on the Moon

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42
Q

Compared to Toronto, where would you look in the sky to find the zenith point in Sydney Australia?

A

straight up

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43
Q

Which Greek school of thought naturally lead to the possibility of the existence extraterrestrial life?

A

atomists

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44
Q

Copernicus

A

revived Aristarchus’s suggestion of a Sun-centered solar system and described it mathematically

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45
Q

Tycho Brahe

A

made detailed measurements of the motions of the planets in the sky

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46
Q

The methods of modern science were originated by the

A

Greeks

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47
Q

Johannes Kepler

A

showed that the orbits of the planets were ellipses and not circles

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48
Q

In its elliptical orbit, a planet is furthest the Sun at

A

aphelion

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49
Q

According to Kepler’s 2nd Law of planetary motion, a planet moves fastest in its orbit when it is

A

at perihelion

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50
Q

The astronomical unit (AU) is defined to be equal to the

A

average distance between the Earth and the Sun

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51
Q

Galileo discovered that Venus goes through a cycle of phases like the Moon. This suggested that

A

Venus moved about the Sun

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52
Q

Asteroid 13681 Monty Python has an orbit with a semi-major axis, a, of 2.99 AU. What is its orbital period?

A

5.17 years

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53
Q

In the scientific method a hypothesis is another name for

A

an educated guess

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54
Q

The apparent angular size of both the Moon and the Sun as seen from Earth are the same, approximately one half of one degree. How many minutes of arc is this equivalent to?

A

30

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55
Q

The four seasons we experience on Earth arise from

A

the tilt (obliquity) of the Earth’s axis

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56
Q

The possibility of extraterrestrial life was first considered

A

many thousands of years ago during ancient times

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57
Q

The observations of sunspots on the Sun and craters on the Moon by Galileo contradicted the commonly held belief that the universe was

A

perfect

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58
Q

Which of the following would need to be true for Kepler’s 3rd Law to apply to an extrasolar planetary system?

A

the parent star would have to have the same mass as the Sun

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59
Q

The astronomical object in our sky which plays the most fundamental role in our lives is the

A

sun

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60
Q

The Ptolemaic model has planets moving in

A

small circles, the centers of which move in a larger circle about the Earth

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61
Q

How would the Solar System be different if the solar nebula had cooled with a temperature half its current value?

A

Jovian planets would likely have formed closer to the Sun

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62
Q

A star that is less massive than the Sun will have

A

a longer lifetime since its central nuclear-burning core is cooler

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63
Q

Apart from terrestrial planets, another promising place to find life in the solar system is

A

beneath the surfaces of icy Jovian moons

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64
Q

Human beings mostly emit which kind of electromagnetic radiation?

A

infrared

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65
Q

Radio rays (waves) travel through space at what speed compared to microwaves?

A

at exactly the same speed as microwaves.

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66
Q

Given the basic building blocks of planets are widespread and the same laws of physics operate everywhere, we would expect

A

other planetary systems to be laid out in a similar manner to our own with inner rocky terrestrial planets and outer gaseous Jovian planets

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67
Q

The most abundant materials in the solar nebula were

A

hydrogen and helium gases

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68
Q

Isotopes have the same number of

A

protons but a different number of neutrons

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69
Q

The reason why the sky appears blue as observed by people from the surface of the Earth is

A

the atmosphere scatters blue light from the Sun making it appear as if the light is coming from all directions

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70
Q

What kind of energy does sunlight possess?

A

radiative

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71
Q

Place the three phases of water in order of increasing force of interaction between molecules

A

vapor, water, ice

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72
Q

The distance between adjacent peaks of an electromagnetic wave is referred to as its

A

wavelength

73
Q

Spectral line patterns are

A

unique for each element and molecule

74
Q

What observation does not directly support the Big Bang theory?

A

The fusion of hydrogen into helium

75
Q

In the context of life in the universe, which of the following discoveries of astronomy suggests that extraterrestrial life may be constructed in a similar fashion to life on Earth?

A

the chemical elements that make up life on Earth are common

76
Q

Place in the correct sequence of size smallest to largest

A

Planet, Sun, Galaxy, Universe

77
Q

One piece of evidence that supports the Big Bang Theory is

A

the confirmation of the prediction that the universe is made of approximately three-fourths hydrogen and one-fourth helium by mass

78
Q

The Astronomical Unit (AU) is defined as the average distance between

A

the Earth and the Sun

79
Q

The observed spectrum from a star (like our Sun) is

A

an absorption spectrum

80
Q

Which statement is incorrect? (3.1)

A

the structure of all exoplanetary systems is identical to the structure of our solar system.

81
Q

When astronomers observe light from objects in the night sky

A

We are detecting information from the past

82
Q

Due to the incredible size of the universe, our search for extraterrestrial life will probably be limited to within our

A

Milky Way galaxy

83
Q

The process by which molecules escape from a liquid into the gas phase is called

A

evaporation

84
Q

In the outer regions of the solar nebula where temperatures were low

A

in addition to rock and iron, hydrogen compounds also condensed as ices

85
Q

Due to the vast scale of the universe, when we observe a star in the night sky, we are seeing it

A

not as it is now, but as it was in the past

86
Q

Many of the extrasolar planetary systems discovered to date are

A

quite different to our own solar system, many with jovian planets found close to their parent stars

87
Q

Thermal radiation from hot, dense objects produces

A

a continuous spectrum

88
Q

The nuclear fusion process at the core of stars

A

liberates energy by making heavier elements from lighter elements.

89
Q

In galaxies like our home, the Milky Way, the majority of matter is in the form of

A

dark matter

90
Q

In the process of nuclear fusion,

A

two or more nuclei fuse or stick together to form a heavier nucleus whose combined mass is slightly less than the original nuclei

91
Q

The Earth’s geological time scale is divided into four main

A

eons

92
Q

If originally there were X atoms of radioactive isotope present and now there are only X/16 atoms, how many half-lives have elapsed?

A

4

93
Q

Without the greenhouse effect, the global average temperature of the Earth’s surface would be

A

well below the freezing point of water

94
Q

What is the most important role that the carbon dioxide cycle plays in the regulation of the Earth’s climate?

A

it regulates the surface temperature by varying the amount of carbon dioxide in the atmosphere

95
Q

Seafloor spreading on the Earth is the process by which

A

molten lava oozes out between two tectonic plates that are slowly moving apart

96
Q

Fossils of the earliest life are very difficult to identify in very old rocks because it

A

was very simple and microscopic in size

97
Q

Which type or types of rock cannot be dated radiometrically?

A

sedimentary

98
Q

Volcanic eruptions do not contribute to

A

a measurable change in the rate of the Earth’s rotation

99
Q

The strongest of evidence that supports the giant impact model for the formation of the Moon is that the

A

overall composition of Moon rocks returned from the Apollo program is similar to the composition of Earth’s mantle material, except for the absence of volatile elements

100
Q

Smaller worlds are more prone to atmospheric loss via impacts than large worlds because they

A

have weaker gravities

101
Q

When considering the Moon, which statement is incorrect?

A

The Moon has an appreciable atmosphere.

102
Q

When an igneous rock is eroded and then becomes deposited at the bottom of an ocean it turns into

A

a sedimentary rock

103
Q

Geological processes on the Earth’s surface are directly related to

A

internal heat

104
Q

If you were to come back to Earth in 150 million years time, what would a map of the planet look like compared to today?

A

quite different because plate tectonics would have caused a shift in the position of the continents

105
Q

Isotopic analysis of a rock can tell us

A

when the rock formed

106
Q

Which of the following was NOT a source of heat that helped differentiate the Earth?

A

solar radiation

107
Q

Most of the Earth’s carbon dioxide

A

has dissolved in the oceans and is locked up in sedimentary carbonate rocks like limestone

108
Q

Differentiation is a process by which

A

denser materials like iron sank to the center of the Earth while less dense materials like rock rose to the surface

109
Q

If S and P waves pass through all layers from the surface to the core of a planet, what is implied?

A

All layers in the planet are solid

110
Q

Which of the following act as greenhouse gases in the Earth’s atmosphere?

A

carbon dioxide, water vapor, and methane

111
Q

The Earth’s magnetosphere is a

A

volume of space carved out in the solar wind by the Earth’s magnetic field

112
Q

A sterilizing impact is one during which

A

all life on a planet is destroyed

113
Q

The greenhouse effect is the

A

trapping of infrared radiation from the Earth’s surface by greenhouse gases like carbon dioxide, methane, and water

114
Q

The extent of thermal escape in a planetary atmosphere is dependent

A

on the temperature and molecular weight (mass) of the gases in its atmosphere

115
Q

Isotopic analysis of meteorites suggests the Earth and the rest of the solar system formed

A

4.57 billion years ago

116
Q

Chemical analysis of a rock can tell us

A

what the rock is made of (the identity of elements within it)

117
Q

The deep interior of the Earth is studied using

A

seismic waves

118
Q

Rocks are found on the surface of another planet which appear to have once been transformed at high temperatures deep within the planet. Given this, they are most likely to be classified as

A

Igneous, Metamorphic

119
Q

Fossils typically contain little or no organic matter because

A

inorganic minerals have gradually replaced the organic matter over time

120
Q

Which component of Earth’s geology has helped to shield the Earth’s atmosphere from energetic particles of solar wind from the Sun which would have gradually stripped it away into space?

A

global magnetism

121
Q

What can be said about the presence of order in living organisms?

A

it is a necessary condition, but not a sufficient condition for life

122
Q

The basic molecular building blocks of proteins are

A

amino acids

123
Q

Any change in the base sequence of an organism’s DNA is referred to as a

A

mutation

124
Q

What is the complementary sequence corresponding to the DNA fragment AGTCAG?

A

TCAGTC

125
Q

Traits passed from parents to offspring are referred to by biologists as

A

heredity

126
Q

What is the MOST important role that proteins play in living organisms on Earth?

A

basic functioning of living organisms

127
Q

Metabolism is a term that describes the

A

chemical processes that occur inside cells

128
Q

The tree of life

A

illustrates the biochemical and genetic relationships between the different domains of life

129
Q

The ability of an animal to improve its sense of smell is best thought of as

A

an adaptation to its environment, improving its chance of survival.

130
Q

All life on Earth share many common characteristics and a common ancestry. Which of the following is not one of these characteristics?

A

Photosynthesis is the primary energy source.

131
Q

What is the maximum number of other atoms that carbon can bond to?

A

4

132
Q

Amino acids found in protein in life on Earth are

A

all left-handed molecules

133
Q

Which is the correct order of structural size, from smallest to largest.

A

Base, Gene, DNA molecule, Cell

134
Q

What is the MOST important role that lipids play in living organisms on Earth?

A

long-term energy storage and cell membranes

135
Q

Organisms that can survive at very low temperatures are referred to as

A

psychrophiles

136
Q

Plants get their energy directly from the Sun and their carbon from the atmosphere. Given this, they can be classified metabolically as

A

photoautotrophs

137
Q

The basic biological structures of life on Earth are called

A

cells

138
Q

The first scientist to suggest that life might evolve through time was

A

Darwin

139
Q

The DNA molecules within a cell consist mainly of

A

carbon, oxygen, hydrogen

140
Q

The most basic definition of life which takes account of the relative importance of the six fundamental properties of living things is that life is something that can

A

reproduce and evolve through natural selection

141
Q

Energy utilization in living organisms is

A

one of the most basic requirements of life, without which organisms could not maintain order, grow, and reproduce

142
Q

Life on Earth can use a variety of different carbon and energy sources. However, the one thing that no organism on Earth can survive without is

A

liquid water

143
Q

What is the main factor that drives Darwinian evolution?

A

the competition for finite resources

144
Q

Chemists refer to molecules containing carbon atoms as

A

organic

145
Q

In cells, living matter inside is separated from the outside world by a barrier called

A

membrane

146
Q

What would you least expect to find in a cell?

A

carbon dioxide (CO2)

147
Q

A photoheterotroph gets its energy from

A

the Sun and its carbon from other organisms

148
Q

When humans get hot, they sweat in order to reduce their body temperature. Which of the key properties of life is this an example of?

A

response to environment

149
Q

The fact that all cells used in life on Earth are based on the same biochemistry suggests that

A

all life on Earth shares a common ancestor

150
Q

The resistance of bacteria to certain antibiotics is a current example of

A

natural selection

151
Q

Why do we think that DNA was probably NOT the first self replicating molecule?

A

it is far to complex to have been the first self replicating molecule

152
Q

Stromatolites are

A

layers of sediment that once contained colonies of ancient microbes

153
Q

One theory for the origin of life suggests that life was transported to Earth in meteorites. This is referred to as

A

panspermia

154
Q

One factor that hampers the use of Miller Urey experiments in studying the chemical processes that may have occurred on the early Earth is that the

A

composition of the Earth’s early atmosphere is not well known

155
Q

Current geological evidence suggests that life

A

could have appeared more than 3.85 billion years ago

156
Q

The largest genetic diversity found on the Tree of Life is in which domain?

A

eukarya

157
Q

A sample of an ancient sedimentary rock contains slightly less of the isotope carbon 13 than normal. One possible explanation for this is that

A

some kind of biological activity occurred in it in the past

158
Q

Prior to the Cambrian Period, life consisted of

A

single celled organisms

159
Q

Did dinosaurs and humans coexist on Earth at the same time?

A

never

160
Q

By studying the Tree of Life scientists have been able to deduce that life on Earth most likely

A

originated close to deep sea volcanic vents

161
Q

An explosion of genetic diversity similar to that which occurred during the Cambrian Period hasn’t happened recently, most likely because

A

of the widespread presence of efficient predators that make it much more difficult for entirely new organisms to appear

162
Q

Based on your knowledge of the timeline for the development of life on Earth, when did the raw material for “fossil fuels” (eg oil) get deposited?

A

360 million years ago

163
Q

What was one reason that RNA was eventually replaced by DNA as the molecule of choice for storing genetic information?

A

the double helix of DNA is better able to correct errors in replication

164
Q

The possibility of life being transferred from another planet like Mars largely depends on whether that life can survive

A

long enough in space to make the journey to Earth

165
Q

Impacts of large asteroids on the Earth’s surface generally result in

A

the destruction of most but not all life on Earth

166
Q

Why can studies of carbon isotopes be used to detect the presence of past biological activity in rocks?

A

living organisms absorb certain carbon isotopes more easily than others

167
Q

What is the K T boundary?

A

a layer of dark sediment in the geological record separating the Cretaceous and Tertiary periods of Earth’s history

168
Q

The most common isotope of carbon is

A

carbon 12

169
Q

Aerobic organisms first started building up oxygen in the Earth’s atmosphere in a significant way around

A

2.4 billion years ago

170
Q

When considering early life on Earth, which statement is correct?

A

There were many sources that provided amino acids on the Earth.

171
Q

Which statement regarding the dating of life on Earth is correct?

A

Evidence suggests that primitive life existed earlier than 3.5 billion years ago

172
Q

Life probably did not originate on the land surface because

A

there was no ozone layer to shield out harmful UV rays

173
Q

As life on Earth evolved, its DNA

A

became gradually more complex

174
Q

The very first living organisms on the Earth were probably

A

chemoautotrophs

175
Q

Where in the Tree of Life will current organisms be located that are most closely related to the common ancestor of all life on Earth?

A

very close to the root

176
Q

Sources of organic molecules on the surface of the early Earth likely did not include

A

sulphur dioxide

177
Q

Why do we not see evidence of more crater impacts on Earth?

A

Weathering and oceans erase the evidence

178
Q

What planetary conditions are most likely to allow a panspermia type relocation of life?

A

A small terrestrial world like Mercury

179
Q

The colonization of life onto land was closely tied to the

A

development of the ozone layer

NATS 1880 Midterm (1 decks)

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