Version A

Write your name at the top of this quiz as well as on your answer sheet, and hand them both in at the end of the quiz. WRITE YOUR VERSION ON YOUR ANSWER SHEET. Feel free to write or draw on the quiz.

SELECT THE BEST ANSWER TO EACH PROBLEM.

1. What does the third term in the Drake Equation, n_e, stand for?
a) The number of elements in a molecule.
b) The number of extraterrestrial civilizations in the Universe.
c) The albedo of a planet.
d) The number of `rungs' in a DNA molecule.
e) The average number of habitable planets per solar system.

e) The average number of habitable planets per solar system.

2. The Earth's magnetic field protects us from:
a) infrared light from the Sun.
b) asteroids.
c) comets.
d) fast-moving charged particles from the Sun.
e) ultraviolet light from the Sun.

d) fast-moving charged particles from the Sun.

3. The Greenhouse Effect on Venus:
a) Is about the same as that on Earth, and stronger than Mars'.
b) Is the same as that on Mars, and less than that of Earth's.
c) Is much greater than both Earth's and Mars'.
d) Venus, Earth, and Mars all have about the same Greenhouse Effect.
e) There is no Greenhouse Effect on Venus.

c) Is much greater than both Earth's and Mars'.

4. In the double helix structure of DNA, two long strands of molecules are connected by `rungs', like the rungs in a ladder. The `rungs' are made of:
a) nitrogeneous bases.
b) methane.
c) deoxyribose sugar.
d) phosphates.
e) polycyclic aromatic hydrocarbons and benzene.

a) nitrogeneous bases.

Also gave credit for c) deoxyribose sugar for this problem, since the sugar is at the intersection of the rungs and the strands.

5. The bonds connecting cytosine and guanine in DNA are:
a) ionic bonds.
b) covalent bonds.
c) phosphodiester bonds.
d) deoxyribose bonds.
e) hydrogen bonds.

e) hydrogen bonds.

6. The bigger the albedo of a planet, the:
a) the stronger its gravitational field.
b) the stronger its magnetic field.
c) the lower its surface temperature.
d) the more iron in its core.
e) all of the above.

c) the lower its surface temperature.

7. A covalent bond is:
a) when a positively-charged ion is attracted to a negatively-charged ion.
b) when a pair of electrons is being shared between two atoms.
c) an attraction between an unshared pair of electrons in one molecule and a hydrogen nucleus in another molecule.
d) a bond between two bases in DNA.
e) when the gravitational pull from a star on a planet is strong enough to keep the same face of the planet pointing towards the star at all times.

b) when a pair of electrons is being shared between two atoms.

8. A ball of mostly hydrogen gas with mass between 0.013 M(sun) and 0.08 M(sun) does not have enough gravitational field to start hydrogen fusion, but may have some deuterium fusion. Such objects are called:
a) black holes.
b) brown dwarfs.
c) white dwarfs.
d) planets.
e) stars.

b) brown dwarfs.

9. If a star cluster contains only G, K, and M main sequence stars, astronomers estimate its age to be about:
a) 1 thousand years old.
b) 1 million years old.
c) 10 million years old.
d) 100 million years old.
e) 10 billion years old.

e) 10 billion years old.

10. The extrasolar planets found so far differ from the planets in our solar system in what way?
a) on average, they are closer to their star than the Sun's planets.
b) on average, they have more elliptical orbits than the Sun's planets.
c) they are generally more massive than the Earth, Venus, and Mars.
d) all of the above.
e) at the present time, we do not know the orbital shape or distance to their star of the extrasolar planets, thus we cannot compare.

d) all of the above.

11. The atmosphere of Venus is mostly:
a) CO₂.
b) O₂.
c) NH₃.
d) CH₄.
e) N₂.

a) CO₂.

12. What is the probable reason that Mars does not have a strong magnetic field, unlike Earth?
a) It is spinning too slowly.
b) It is probably solid throughout, without a liquid outer core.
c) It is both solid throughout, and is spinning too slowly.
d) Mars does have a very strong magnetic field, like Earth.
e) We do not know yet if Mars has a global magnetic field like Earth's.

b) It is probably solid throughout, without a liquid outer core.

13. Which of the following molecules contribute most strongly to the Greenhouse Effect on Earth?
a) N₂ and O₂.
b) CO₂, H₂O, and CH₄.
c) Neon and helium.
d) H₂.
e) iron.

b) CO₂, H₂O, and CH₄.

14. The Messenger spacecraft's primary target is:
a) Mercury.
b) Venus.
c) Jupiter and its moons.
d) Saturn and its moons.
e) Pluto.

a) Mercury.

15. Which spacecraft is currently about 100 A.U. from the Earth, and is still sending messages back to the Earth?
a) Messenger.
b) New Horizon.
c) Spirit.
d) Cassini.
e) Voyager 1.

e) Voyager 1.

16. As an interstellar gas cloud gravitationally contracts in the process of forming into a star and planets:
a) its spin rate stays the same, as does its shape.
b) its spin rate stays the same, and it flattens to a disk.
c) its spin rate decreases, and it flattens to a disk.
d) its spin rate increases, and it flattens to a disk.
e) its spin rate increases, and it expands from a disk into a spherical shape.

d) its spin rate increases, and it flattens to a disk.

17. Interstellar matter is:
a) about 99 percent hydrogen and helium.
b) about half gas, half dust.
c) about 99 percent dust, 1 percent gas.
d) completely ionized.
e) may not exist; it has never been detected.

a) about 99 percent hydrogen and helium.

18. The volume of space around a star in which liquid water can exist on the surface of a planet is called the:
a) Water Belt.
b) The Greenhouse Zone.
c) The Hydrocarbon Regime.
d) The Habitable Zone.
e) The Sublimation Belt.

d) The Habitable Zone.

19. In chemistry, the term `hydrogen bond' refers to:
a) When two atoms share a pair of electrons.
b) The attraction between a positive ion and a negative ion.
c) The bond between two hydrogen atoms in molecular hydrogen H₂.
d) an attraction between an unshared pair of electrons in one molecule and a hydrogen nucleus in another molecule.
e) The bond between carbon and hydrogen in methane.

d) an attraction between an unshared pair of electrons in one molecule and a hydrogen nucleus in another molecule.

20. The Greenhouse Effect involves the absorption of what kind of light from the Earth by molecules in the Earth's atmosphere?
a) gamma rays.
b) UV.
c) infrared.
d) X-rays.
e) all of the above.

c) infrared.