Mastering Astronomy study test 1 part 1 Flashcards Preview

Astronomy > Mastering Astronomy study test 1 part 1 > Flashcards

Flashcards in Mastering Astronomy study test 1 part 1 Deck (70):
1

Most of the charged particles from the Sun are deflected around Earth by the?

Magnetosphere

2

Earth's _____ absorbs most of the ultraviolet light arriving here from the Sun.

Stratosphere

3

Most of the X-rays coming from the Sun are absorbed in the ______

Thermosphere

4

Gas particles in Earth's atmosphere most easily escape from the____

Exosphere

5

The densest layer of the atmospheres of Venus, Earth, and Mars is the ______

Troposphere

6

Which of the following is NOT a major pattern of motion in the solar system?

A. Most of the solar systems large moons orbit in their planets equatorial plane.
B. All of the planets orbit the Sun in the same direction - counterclockwise as viewed from above Earths north pole
C. Nearly all comets orbit the Sun in the same direction and roughly the same plane.
D. The sun and most of the planets rotate in the same direction in which the planets orbit the Sun.

C. Nearly all comets orbit the Sun in the same direction and roughly the same plane.

7

Which of the following is not a major difference between the terrestrial and jovian planets in our solar system?

A. Terrestrial planets are higher in average density than jovian planets.
B. Terrestrial planets orbit much closer to the Sun than jovian planets.
C.Jovian planets have rings and terrestrial planets do not.
D.Terrestrial planets contain large quantities of ice and jovian planets do not.

D.Terrestrial planets contain large quantities of ice and jovian planets do not.

8

Consider the following statement: "Rocky asteroids are found primarily in the asteroid belt and Kuiper belt while
icy comets are found primarily in the Oort cloud." What's wrong with this statement?

A. Comets are not really icy.
B. Asteroids are not really made of rock.
C. The Oort cloud has nothing to do with comets.
D. The Kuiper belt contains icy comets, not rocky asteroids.
E. The statement is accurate as written.

D. The Kuiper belt contains icy comets, not rocky asteroids.

9

Which of the following is not a real difference between asteroids and comets?

A. It is thought that comets are far more numerous than asteroids.
B. Asteroids are made mostly of rock and comets are made mostly of ice.
C. Most asteroids are located much nearer to the Sun than most comets.
D. Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.

D. Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.

10

The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system?

A. The diameter of Earth's Moon is about 1/4 that of Earth.
B. Jupiter has a very small axis tilt.
C. Saturn has no solid surface.
D. Venus does not have a moon.

A. The diameter of Earth's Moon is about 1/4 that of Earth.

11

Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is ______.

A. much smaller
B. much larger
C. about the same
D. just slightly less

B. much larger

12

How is Einstein's famous equation, E=mc2, important in understanding the Sun?

A. It explains why the Sun has a magnetic field strong enough influence the atmospheres of the planets.
B. It explains why the Sun is so massive.
C. It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each second.
D. It explains why the Sun's surface temperature is about 6,000°C.

C. It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each second.

13

Venus has a higher average surface temperature than Mercury. Why?

A. Because its surface is covered with hot lava from numerous active volcanoes.
B. Because it is closer to the Sun.
C. Because its slow rotation gives it more time to heat up in sunlight.
D. Because its surface is heated by an extreme greenhouse effect.

D. Because its surface is heated by an extreme greenhouse effect.

14

In what way is Venus most similar to Earth?

A. Both planets have warm days and cool nights.
B. Both planets have similar surface geology.
C. Both planets are nearly the same size.
D. Both planets have very similar atmospheres.

C. Both planets are nearly the same size.

15

Which of the following statements about the object called Eris is not true?

A. It lies well beyond Pluto and Neptune.
B. It is slightly larger in mass than Pluto.
C. It is thought to be the first example of a new class of object.
D. It orbits the Sun in the same general direction as the planets.

C. It is thought to be the first example of a new class of object.

16

Mars has two moons that are most similar in character to:

A. Earth's Moon
B. comets.
C. small asteroids
D. particles in the rings of Saturn

C. small asteroids

17

Imagine that an alien spaceship crashed onto Earth. Which statement would most likely be true?

A. All the evidence of the crash would be quickly whisked off by the U.S. military to Area 51 in Nevada.
B. The crash would create a noticeable crater.
C. It would crash in the ocean.
D. The aliens' home world is another planet in our own solar system.

C. It would crash in the ocean.

18

Which planet listed below has the most extreme seasons?

A. Jupiter
B. Mars
C. Uranus
D. Earth

C. Uranus

19

In what way is Pluto more like a comet than a planet?

A. It has moons.
B. It sometimes enters the inner solar system.
C. It is made mostly of rock and ice.
D. It has a long tail.

C. It is made mostly of rock and ice.

20

Why was it advantageous for the Voyager mission to consist of flybys rather than orbiters?

A. It was easier for data to be radioed back to Earth with flybys than orbiters.
B. Flyby spacecraft can get closer to a planet than an orbiting spacecraft.
C. Spacecraft making flybys can return to Earth more quickly than orbiters.
D. Each individual spacecraft was able to visit more than one planet.

D. Each individual spacecraft was able to visit more than one planet.

21

Why has NASA sent recent orbiters to Mars (such as Mars Reconnaissance Orbiter) on trajectories that required them to skim through Mars's atmosphere before settling into their final orbits?

A. It allowed the orbiters to get higher resolution pictures of the surface as it came close when skimming through the atmosphere.
B. It allowed the spacecraft to collect samples of the atmospheric gas for return to Earth.
C.Each spacecraft also carried a lander, and the lander could only be dropped to the Martian surface when the spacecraft passed through the atmosphere.
D. It saves money because the spacecraft uses atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines.

D. It saves money because the spacecraft uses atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines.

22

In essence, the nebular theory holds that _________.

A. our solar system formed from the collapse of an interstellar cloud of gas and dust
B. the planets each formed from the collapse of its own separate nebula
C. nebulae are clouds of gas and dust in space
D. The nebular theory is a discarded idea that imagined planets forming as a result of a near-collision between our Sun and another star.

A. our solar system formed from the collapse of an interstellar cloud of gas and dust

23

According to modern science, what was the approximate chemical composition of the solar nebula?

A. Roughly equal proportions of hydrogen, helium, water, and methane.
B. 50% hydrogen and helium, 50% everything else
C. 98% hydrogen and helium, 2% everything else
D. 98% hydrogen, 2% helium

C. 98% hydrogen and helium, 2% everything else

24

According to our present theory of solar system formation, which of the following lists the major ingredients of the solar nebula in order from the most abundant to the least abundant?

A. hydrogen and helium gas; hydrogen compounds; rock; metal.
B. hydrogen and helium gas; rock; metal.hydrogen compounds
C. hydrogen, water, methane, helium
D. hydrogen compounds; hydrogen and helium gas; metal; rock

A. hydrogen and helium gas; hydrogen compounds; rock; metal.

25

Which of the following types of material can condense into what we call ice at low temperatures?

A. rock
B. hydrogen and helium
C. hydrogen compounds
D. metal

C. hydrogen compounds

26

What do we mean by the frost line when we discuss the formation of planets in the solar nebula?

A. It is another way of stating the temperature at which water freezes into ice.
B. It marks the special distance from the Sun at which hydrogen compounds become abundant; closer to the Sun, there are no hydrogen compounds.
C. It is the altitude in a planet's atmosphere at which snow can form.
D. It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.

D. It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.

27

What do we mean by accretion in the context of planet formation?

A. The formation of moons around planets
B. The solidification of ices, rocks, and metal from the gas of the solar nebular
C. The growth of the Sun as the density of gas increased in the center of the solar nebula
D. The growth of planetesimals from smaller solid particles that collided and stuck together

D. The growth of planetesimals from smaller solid particles that collided and stuck together

28

According to our theory of solar system formation, what are asteroids and comets?

A. The shattered remains of collisions between planets
B. Leftover planetesimals that never accreted into planets
C. Chunks of rock or ice that condensed after the planets and moons finished forming
D. Chunks of rock or ice that were expelled from planets by volcanoes

B. Leftover planetesimals that never accreted into planets

29

According to our theory of solar system formation, where did the comets of the Oort cloud form?

A. in the inner solar system.
B. in the asteroid belt.
C. in the region of the jovian planets
D. far beyond the orbit of Pluto

C. in the region of the jovian planets

30

What is the giant impact hypothesis for the origin of the Moon?

A. The Moon originally was about the same size as Earth, but a giant impact blasted most of it away so that it ended up much smaller than Earth.
B. The Moon formed from material blasted out of the Earth's mantle and crust by the impact of a Mars size object.
C. The Moon formed just like the Earth, from accretion in the solar nebula.
D. The Moon formed when two gigantic asteroids collided with one another.

B. The Moon formed from material blasted out of the Earth's mantle and crust by the impact of a Mars size object.

31

According to our modern science, which of the following best explains why the vast majority of the mass of our solar system consists of hydrogen and helium gas?

A. Hydrogen and helium are the most common elements throughout the universe, because they were the only elements present when the universe was young.
B. Hydrogen and helium are produced in stars by nuclear fusion.
C. All the other elements escaped from the solar nebula before the Sun and planets formed.
D. All the other elements were swept out of the solar system by the solar wind.

A. Hydrogen and helium are the most common elements throughout the universe, because they were the only elements present when the universe was young.

32

nebula ended up with a disk shape as it collapsed?

A. It flattened as a natural consequence of collisions between particles in the nebula.
B. The law of conservation of energy.
C. The force of gravity pulled the material downward into a flat disk.
D. It was fairly flat to begin with, and retained this flat shape as it collapsed.

A. It flattened as a natural consequence of collisions between particles in the nebula.

33

According to our present theory of solar system formation, which of the following statements about the growth of terrestrial and jovian planets is not true?

A. The jovian planets began from planetesimals made only of ice, while the terrestrial planets began from planetesimals made only of rock and metal.
B. Both types of planet begun with planetesimals growing through the process of accretion, but only the jovian planets were able to capture hydrogen and helium gas from the solar nebula.
C. Swirling disks of gas, like the solar nebula in miniature, formed around the growing jovian planets but not around the growing terrestrial planets.
D. The terrestrial planets formed inside the frost line of the solar nebula and the jovian planets formed beyond it.

A. The jovian planets began from planetesimals made only of ice, while the terrestrial planets began from planetesimals made only of rock and metal.

34

According to our present theory of solar system formation, how did Earth end up with enough water to make oceans?

A. The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars.
B. Earth formed in the relatively narrow region of the solar nebular in which liquid water was plentiful.
C. The water was mixed in the other materials in the planetesimals that accreted at our distance from the Sun.
D. The water was formed by chemical reactions among the minerals in the Earth's core.

A. The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars.

35

What is the primary reason that astronomers suspect that some jovian moons were captured into their current orbits?

A. Some moons are surprisingly large in size.
B. Astronomers have observed moons being captured.
C. Some moons have a composition that differs from the composition of the planets
D. Some moons have orbits that are "backwards" (compared to their planet's rotation) or highly inclined to
their planet's equator.

D. Some moons have orbits that are "backwards" (compared to their planet's rotation) or highly inclined to
their planet's equator.

36

Why are terrestrial planets denser than jovian planets?

A. Actually, the jovian planets are denser than the terrestrial planets.
B. Gravity compresses terrestrial planets to a higher degree, making them denser.
C. Only dense materials could condense in the inner solar nebula.
D. The Sun's gravity gathered dense materials into the inner solar system.

C. Only dense materials could condense in the inner solar nebula.

37

About 2% of our solar nebula consisted of elements besides hydrogen and helium. However, the very first
generation of star systems in the universe probably consisted only of hydrogen and helium. Which of the following
statements is most likely to have been true about these first generation
star systems?

A. Jovian planets in these first generation
star systems had clouds made of water and other hydrogen compounds.
B. These first generation star systems typically had several terrestrial planets in addition to jovian planets.
C. There were no comets or asteroids in these first generation star systems.
D. Like the jovian planets in our solar system, the jovian planets in these first generation
systems were orbited by rings.

C. There were no comets or asteroids in these first generation star systems.

38

Which of the following best describes how the greenhouse effect works?

A. Greenhouse gases absorb infrared light coming from the Sun, and this absorbed sunlight heats the lower
atmosphere and the surface.
B. A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.
C.Greenhouse gases absorb Xrays
and ultraviolet light from the Sun, and this absorbed radiation then
heats the atmosphere and the surface.
D. The greenhouse effect is caused primarily by ozone, which absorbs ultraviolet light and thereby makes
the atmosphere much hotter than it would be otherwise.

B. A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.

39

Suppose that Earth's ice caps melted, but everything else about the Earth's surface and atmosphere stayed the same. What would happen to Earth's average surface temperature?

A. The surface temperature would change radically, until it was equal to the melting temperature of ice.
B. The surface temperature would increase.
C. The temperature would not be affected at all.
D. The surface temperature would decrease.

B. The surface temperature would increase.

40

All the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450°C hotter than the surface of Earth?

A. Venus is only about 73% as far from the Sun as Earth.
B. Venus has a higher atmospheric pressure than Earth.
C. Venus has a much higher reflectivity than Earth.
D. Venus has a much stronger greenhouse effect than Earth.

D. Venus has a much stronger greenhouse effect than Earth.

41

In very general terms, how do the temperature structures of the atmospheres of Venus and Mars differ from that of Earth?

A. Temperatures in their tropospheres increase with altitude, rather than decreasing with altitude.
B. Their atmospheres are similar in structure to Earth's, but with much higher temperatures.
C. They lack Xray absorbing thermospheres.
D. They lack ultraviolet absorbing
stratospheres.

D. They lack ultraviolet absorbing
stratospheres.

42

Why is the Coriolis effect so weak on Venus?

A. Because Venus has such a thick atmosphere.
B. Because Venus has such a strong greenhouse effect.
C. Because Venus rotates so slowly.
D. Because Venus is so hot.

C. Because Venus rotates so slowly.

43

All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space?

A. Mars probably once had a much higher density of greenhouse gases in its atmosphere than it does today.
B. The axis tilt of Mars is thought to change significantly with time.
C. Mars lost any global magnetic field that it may once have had.
D. Outgassed water molecules are split apart, and the oxygen then reacts chemically with surface rock on Mars.

C. Mars lost any global magnetic field that it may once have had.

44

What makes us think that Mars must once have had an atmosphere that was warmer and had higher surface pressure?

A. The presence of inactive volcanoes on Mars tells us that there must once have been a lot of outgassing, and hence a thicker atmosphere.
B. The fact that parts of Mars have a lot of craters tell us that Mars must once have been much warmer.
C. The atmosphere is too cold and thin for liquid water today, yet we see evidence of flowing water in the past.
D. We think it for purely theoretical reasons, based on calculations showing that the Sun has brightened with
time.

C. The atmosphere is too cold and thin for liquid water today, yet we see evidence of flowing water in the past.

45

What would happen to Earth if we somehow moved our planet to the orbit of Venus?

A. Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus.
B. Temperatures would rise only slightly, but enough to melt the polar caps.
C. Being so much closer to the Sun would almost immediately cause the surface of Earth to melt, and all our cities would then be destroyed by the hot lava.
D. The fact that we have oceans would moderate the temperature change due to moving our planet, so temperature would hardly change at all.

A. Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus.

46

Why does Earth have so little carbon dioxide in its atmosphere compared to Venus?

A. Earth's volcanoes outgassed far less carbon dioxide than those on Venus.
B. Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.
C. Earth once had a lot of carbon dioxide, but it was lost to space during the heavy bombardment early in our solar system's history.
D. Chemical reactions turned Earth's carbon dioxide into nitrogen.

B. Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.

47

Which characteristic of Earth explains why we have an ultraviolet absorbing
stratosphere?

A. the existence of plate tectonics
B. the existence of oceans
C. the existence of photosynthetic life
D. the moderate surface temperature

C. the existence of photosynthetic life

48

According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?

A. Early forms of animal life consumed the oxygen released by plants during the first billion years of life on Earth.
B. Oxygen released by life was removed from the atmosphere by chemical reactions with surface rocks until the surface rock could absorb no more.
C. Oxygen released by life was removed from the atmosphere by dissolving in the ocean until the oceans could dissolve no more.
D. Early life did not release oxygen, and oxygen releasing organisms didn't evolve for a billion years after the earliest life.

B. Oxygen released by life was removed from the atmosphere by chemical reactions with surface rocks until the surface rock could absorb no more.

49

Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by _____.

A. the human release of chemicals called CFCs into the stratosphere
B. the increase in forest fires during recent years
C. human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere
D. the fact that our politicians spout a lot of hot air

C. human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere

50

On a cloudless day, what happens to most of the visible light headed toward Earth?

A. it is reflected by earth's atmosphere
B. it is absorbed and reemitted by gases in Earth's atmosphere.
C. It is completely reflected by Earth's surface.
D. It reaches Earth's surface, where some is reflected and some is absorbed.

D. It reaches Earth's surface, where some is reflected and some is absorbed.

51

On a day with complete cloud cover, what happens to the visible light headed toward Earth?

A. The clouds reflect much of it back to space, though some still reaches the surfaces.
B. It is absorbed by the clouds, which causes the clouds to heat up.
C. it reaches the surface just as it does on a cloudless day.

A. The clouds reflect much of it back to space, though some still reaches the surfaces.

52

What happens to the energy that the ground absorbs in the form of visible sunlight?

A. It is returned upward in the form of infrared light.
B. It is returned upward in the form of visible light.
C. It makes the ground continually get hotter and hotter.

A. It is returned upward in the form of infrared light.

53

The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface_______.

A. Travels directly out to space
B. becomes permanently trapped by greenhouse gases
C. is temporarily absorbed by greenhouse gases and then re emitted in random directions.

C. is temporarily absorbed by greenhouse gases and then re emitted in random directions.

54

Which planet(s) have an atmosphere that consists mostly of carbon dioxide?

A. Venus only
B. Venus, Earth, and Mars
C. Mars only
D. Venus and Mars

D. Venus and Mars

55

Why does atmospheric pressure decrease as you go higher in altitude on Earth?

A. There are fewer greenhouse gases at higher altitude.
B. Temperature decreases with altitude and lower temperature tends to mean lower pressure.
C. Gravity gets much weaker with altitude.
D. The weight of the atmosphere above you decreases with altitude.

D. The weight of the atmosphere above you decreases with altitude.

56

Which of the following is the most basic definition of a greenhouse gas?

A. a gas that keeps warms air from rising, and therefore warms the surface
B. a gas that reflects a lot of sunlight
C. a gas that absorbs infrared light
D. a gas that makes a planet much hotter than it would be otherwise, even in small amounts

C. a gas that absorbs infrared light

57

Which of the following is not a greenhouse gas?

A. oxygen (O2)
B. carbon dioxide (CO2)
C. water vapor (H2O)
D. methane (CH4)

A. oxygen (O2)

58

Suppose that Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would
be _______.

A. slightly warmer, but still well below the boiling point of water
B. slightly cooler, but still above freezing
C. well below the freezing point of water
D. about the same as it is now

C. well below the freezing point of water

59

Which of the following correctly lists the layers of Earth's atmosphere from the ground upward?

A. troposphere, stratosphere, thermosphere, exosphere
B. thermosphere, stratosphere, troposphere , exosphere
C. troposphere, thermosphere, stratosphere, exosphere
D. exosphere, stratosphere, thermosphere, troposphere

A. troposphere, stratosphere, thermosphere, exosphere

60

Why is the sky blue (on Earth)?

A. Because molecules scatter blue light more effectively than red light.
B. Because deep space is blue in color.
C. Because the Sun emits mostly blue light.
D. Because molecules scatter red light more effectively than blue light.
E. No one knows this is one of the great mysteries of science.

A. Because molecules scatter blue light more effectively than red light.

61

Which of the following general statements about light and Earth's atmosphere is not true?

A. Ultraviolet from the Sun is absorbed in the stratosphere.
B. Visible light from the Sun is absorbed in the exosphere.
C. Xrays from the Sun are absorbed in the thermosphere.
D. Infrared light emitted by Earth itself is absorbed in the troposphere.

B. Visible light from the Sun is absorbed in the exosphere.

62

What is the difference between weather and climate?

A. Weather refers to small storms and climate refers to large storms.
B. Weather is something that we can control, and climate is not.
C. Weather refers to short term
changes in wind, rain, and temperature, while climate refers to the long term average of weather.
D. Weather refers to atmospheric conditions in the troposphere, while climate refers to atmospheric
conditions in the stratosphere.

C. Weather refers to short term
changes in wind, rain, and temperature, while climate refers to the long term average of weather.

63

What important change in the Sun over the past four billion years is thought to be very important to understanding the climates of Venus, Earth, and Mars?

A. a gradual brightening with time
B. a gradual dimming with time
C. a gradual reduction in the amount of ultraviolet and Xray radiation coming from the Sun
D. a gradual weakening of the solar wind with time

A. a gradual brightening with time

64

Which of the following best describes the nature and origin of the atmospheres of the Moon and Mercury?

A. They have thin tropospheres only, with gas coming from evaporation and sublimation.
B. They have very thin atmospheres produced by out gassing, but still have the layers of a
troposphere, thermosphere, and exosphere.
C. They have thin exospheres only, with gas coming from impacts of subatomic particles and photons.
D. They have only small amounts of gas, all of which is leftover from out gassing long ago.

C. They have thin exospheres only, with gas coming from impacts of subatomic particles and photons.

65

Which of the following is not a characteristic of the seasons on Mars?

A. The seasons last almost twice as long on Mars as on Earth.
B. As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect.
C. Global winds tend to blow from the summer pole toward the winter pole, sometimes initiating global sand storms.
D. The polar caps shrink in summer and grow in winter.

B. As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect.

66

What do we mean by a runaway greenhouse effect?

A. a process that heats a planet like a greenhouse effect, but that involves a completely different mechanism of heating that doesn't actually involve greenhouse gases
B. a greenhouse effect that starts on a planet but later disappears as gases are lost to space
C. a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere
D. a greenhouse effect that heats a planet so much that its surface rock melts

C. a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere

67

Based on everything we have learned about Venus and Mars, what is the most surprising aspect of Earth's climate history?

A. The fact that the temperature of our planet has remained relatively steady throughout our planet's history.
B. The fact that Earth had enough water to form oceans.
C. The fact that Earth's climate can be affected by changes in its axis tilt.
D. The fact that Earth apparently got a lot of atmospheric gas from outgassing by volcanoes.

A. The fact that the temperature of our planet has remained relatively steady throughout our planet's history.

68

Which of the following statements about ozone (in Earth's stratosphere) is not true:

A. Ozone is a form of oxygen.
B. Ozone absorbs harmful ultraviolet light from the Sun.
C. The presence of ozone was crucial to the origin of life some 4 billion years ago.
D. Without this ozone, Earth would not have a stratosphere.

C. The presence of ozone was crucial to the origin of life some 4 billion years ago.

69

How did molecular oxygen (O2) get into Earth's atmosphere?

A. It was released by life through the process of photosynthesis.
B. It came from chemical reactions with surface rocks.
C. It was out gassed from volcanoes.
D. It was captured from the solar nebula.

A. It was released by life through the process of photosynthesis.

70

Which of the following is not an expected consequence of global warming?

A. Melting of polar ice and glaciers.
B. An increase in the number and intensity of hurricanes.
C. An increase in the severity of winter blizzards.
D. The entire Earth will warm up by the same amount.

D. The entire Earth will warm up by the same amount.