Use these questions to test your understanding. If you get them wrong, you will be linked back to the relevant part of the notes. 

Be sure you study them thoroughly (don't just get a quick fix for your mistake) so your overall understanding is improved.

1. A disaster in which a large asteroid or comet strikes the earth is

    a. unlikely because all such objects have been cleared away over the billions years the earth has gone around its orbit.

    b. unlikely because the moon can shield us from such events.

    c. unlikely because the asteroids are all in the asteroid belt the the comets in the Oort cloud, far away from Earth.

    d. bound to happen sooner or later because the giant planets keep deflecting such objects into chaotic orbits

    e. nothing to worry about because we can break it up with missiles and bombs

2. "Chaos" means ___________ to a scientist

    a. the behavior of a system where very small changes can have very large consequences

    b. the behavior of a NatSci102 class 30 seconds before the end of the lecture period

    c. that he/she does not understand a system, but a more clever scientist might

    d. the state of the dinosaur population right after the K/T impactor hit

    e. the spray of fragments when an asteroid slams into a planet

3. The means by which the K/T impactor probably killed most of the dinosaurs is

    a. fragments hit them on the head and fractured their skulls.

    b. it disrupted the mantle of the earth and led to huge volcano eruptions.

    c. they suffocated from noxious fumes emitted by the impactor.

    d. carbon dioxide was released that caused a huge greenhouse effect.

    e. material hurled up into space came back down, heating up to high temperature when it struck the atmosphere and baking them.

4. After the K/T disaster,

    a. the first mammals appeared.

    b. small reptiles had survived, and they evolved into the first mammals.

    c. primitive mammals like opossums became abundant relatively quickly.

    d. only sea animals had survived because of the horrendous conditions on land; land life evolved from the sea.

    e. large, complex mammals took over the earth quickly.

5. Mass extinctions

    a. appear to all arise from collisions of asteroids or comets with the earth.

    b. occur roughly every hundred million years, probably from a variety of causes.

    c. have only occurred once or twice in the history of the earth.

    d. are responsible for the emergence of new species of animals every million years or so.

    e. have been decreasing rapidly in frequency over the last billion years.

6. Evidence that an asteroid or comet killed the dinosaurs in the K/T extinction includes:

    a. the existence of a giant crater off the Yucatan Peninsula, and observations of the recent impacts of a comet on Jupiter

    b. a thin layer of iridium-rich material in rock around the earth

    c. both a. and b.

    d. the dinosaur death rate was highest on the Yucatan Peninsula

    e. there is evidence of a huge blast wave from petrified trees that all fell in the same direction.

7. High iridium content indicates an object came from space because:

    a. there is very little iridium in the earth

    b. iridium is manufactured in the high pressure and temperature of a collision

    c. iridium is made only in supernova explosions

    d. iridium is a heavy material and therefore most of that in the earth has sunk to the center

    e. the iridium on the surface of the earth is locked up in strong rocks.

8. Evidence that large asteroids hit the earth from time to time includes

    a. eyewitness accounts

    b. evidence for huge tidal waves

    c. the record of craters on other solar system bodies

    d. petrified trees all aligned away from the impact sites

    e. theoretical calculations of the frequency such impacts are expected