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. Multiple forms of complex animal life first appeared
a. after the K/T extinction. b. more than 3 billion years after the first life on Earth.
c. fairly quickly after the first life on Earth. d. as soon as nucleated cells developed.
e. once there was substantial oxygen in the atmosphere for them to breathe.
2. Sex was an important development toward advanced life because:
a. it makes the world go 'round.
b. it made animals want to reproduce more.
c. it greatly increased the genetic variety in living organisms
d. actually, it was not that big a deal.
e. we are not sure of its importance.
3. Nucleated, complex cells appear to have formed
a. by a mutation that created them directly from simple, un-nucleated cells
b. by cells developing ways to live together to their mutual advantage
d. within a few hundred million years of the end of the intense bombardment of the early earth.
e. once sex had been established.
4. Many Cambrian creatures are related to
a. arthropods, the group that includes spiders, insects, crabs, lobsters
b. vertebrates, the group that includes fish, amphibians
c. they had little relation to surviving life forms
d. fungi, the group that includes mushrooms, tree ears
5. The rapid development of a broad variety of animals in the Cambrian period occurred
a. because of the development of complex cells
b. the creatures are so unique, they must have come from another planet
c. for reasons we are not entirely sure of, although we have a number of ideas
d. because of the sudden availability of atmospheric oxygen
e. because continents had developed.
6. A new development with the Cambrian creatures overall was
b. ability to operate on dry land
c. predators that fed on other animals
d. warm blood and high metabolism
7. Judging by how long it took to happen, the most difficult step toward complex life was
a. development of bacteria that could reproduce and make food from water and carbon dioxide
b. development of nucleated cells
d. development of predators and defensive mechanisms
e. leaving the oceans for operation on land